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What’s The Best Time of Year to Visit Thailand?

When is the Best Time to Visit Thailand

When is the Best Time to Go to Thailand?

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Pick up any travel magazine or visit any website about Thailand and you’ll be greeted with photos of blue skies, sun-kissed beaches and mountain vistas with sweeping panoramic views.  But I’ve got some news for you . . . it isn’t like that all the time.  

The best time to visit Thailand is during the dry season which, in most areas of the country, runs from November through until March. However this is also the busiest and most expensive time of year to visit.  And at other times of year, the weather can be just as bad in Thailand as it is in Europe or the US. Well, maybe it’s a little warmer here, but we do get grey skies and storms and temperatures have been known to dip below 16°C (60°F) overnight.

If you don’t want to waste your short vacation time in Thailand you’ll need to plan when to visit and where to go.  And not just rely on luck in order to have the best chance of stepping off the plane and into that cloudless postcard image of Thailand you’re dreaming of. 

Fortunately, with some advance planning visitors can travel outside the dry season, save money on flights and hotel rooms and still get great weather. 

This guide will show you which regions of Thailand to consider visiting at different times of year.

The Seasons in Thailand

The rainy season isn’t uniform across the country. But in general, from May to October you can expect some rain.  Just how much rain you get depends on where you are visiting and whether the weather gods are on your side.  On the plus side, this time of year is the best time to visit Thailand to enjoy a wide range of fruit at low prices is at this time of year.  It’s the main fruit harvesting season.

So instead of having a spring, summer, fall, and winter most regions of Thailand experience three tropical seasons.  These are Hot, Wet and Cool. 

The Hot Season.  It runs from March to mid-May.  You can expect 35°C+ temperatures in the central and northern areas of the country.  

The Wet Season.  This lasts from mid-May to October and is due to the southwest monsoon.  

The Cool Season. From  November to February.  Mostly dry and with cooler temperatures than the rest of the year.  This is due to the north-east monsoon which brings cooler air down from China.  However, the north of Thailand feels the effects of the cooler air much more than the south. 

However, there are exceptions for example in the south of Thailand the islands on the west and east of the country have different seasons. The area around the Andaman coast, Phuket and Krabi, doesn’t have the same weather patterns as Samui and Koh Pa-Ngan over in the Gulf of Thailand. The wettest months on the west coast are from April to October but the east receives most of its rainfall during the period from September to December.

And man-made environmental factors also have to be considered when planning your trip.

For example, if you’re visiting the north of Thailand ‘burning season’ has to be factored in to your plans.  As booking two weeks in Chiang Mai only to discover the town is cloaked in choking smoke is something many visitors inadvertently do each year.  At the end of every dry season farmers prepare the fields for new crops. 

The quickest and cheapest method is to burn the fields.  This is illegal, but the authorities seem either unwilling or powerless to stop it. Despite the negative effects on the heath of people living in the north of Thailand.

Sunshine on a beach in Phuket

The Climate and Weather in Thailand

Let’s look at the country in a bit more detail now.  I’ve split it into three regions covering the most popular tourist destinations.  And then I’ll get into the actual temperatures and rainfall figures for specific locations. 

The Climate in Central and North Thailand 

This includes Bangkok, Kanchanaburi, Ayuttaya, Chiang Mai, Chiang Rai, and Pai

The best time to visit is during the long dry season.  This usually last from November until May.  There’s not much rain during this period, aside from some thunderstorms or localized showers. Temperatures can be cool during December and January.  Pack a light fleece or sweater for cool nights.  But they begin to rise in February and hit their peak during the hottest months of the year from March to May. You can expect 35°C or more (95°F) in Bangkok. 

And days over 40°C (105°F) are increasingly common in the central plains around Kanchanaburi Ayuttaya and Sukhothai.  It’s always a bit cooler at altitude in the north but it can still reach 35°C(95°F) in Chiang Mai and Pai. 

As the rainy season nears, clouds gather and the humidity shoots up to uncomfortable levels. You will sweat just standing still.  The south-west monsoon affects the climate from May to July. The daily rainfall builds up during this period.  Many days in May or June just have short showers and there’s still plenty of sunshine.  But as you move into August and September the number of storms increases and the rain becomes heavier and more persistent during the day. 

From late September through October the temperature will cool a little and humidity levels decrease as the rainfall reduces and the days get brighter and sunnier. 

By November, dry weather will have returned to most areas of Central and North Thailand.  Once the northeast monsoon begins, signified by a cooler north wind blowing, temperatures in the north can dip below 20C.  You’ll need to pack accordingly, as whilst the north of Thailand is beautiful in January, it’s not place for shorts and a t-shirt.  Especially after sunset or early morning when the air is crisp and clear.  

The Climate on the Andaman Coast

The Andaman Sea is the body of water located to the south-west of Thailand.  As such the area encompassing Phuket, Krabi, Koh Lanta and Koh Phi Phi is often referred to as the Andaman Coast

The west coast has three easily defined seasons.  The cool winter season with an average temperature of 26 – 30°C (80 – 88°F) lasts from November to March.  It’s a good time to visit as the cool breeze keeps humidity levels low and visitors can expect mostly dry days with plenty of sunshine. 

From March to May, as the hot summer months kick in, the average daily temperature and humidity rise.  Daily highs are from 30°C-35°C (88 – 95°F) 

At some point in May the annual monsoon will arrive.  Although the Andaman coast doesn’t receive any direct hits from the cyclones which originate in the Indian ocean, their effects are felt.  The trailing edge of a cyclone is enough to cause rough seas and persistent grey, rainy days, as it passes by.  Outside passing cyclones, the daily pattern is for short tropical downpours in the afternoon.

Phuket and the Andaman coast also has the best air quality in the country.  Which is a major plus for any visitors who are susceptible to pollution.  

The Climate in the Gulf of Thailand

The Gulf of Thailand includes the islands of Koh Samui, Koh Phan Ngan, Koh Tao, Koh Samet, Koh Chang, Koh Kood plus coast areas of Hua Hin and Pattaya

In this area of Thailand, visitors can expect the best weather between December and February.  During this time there is rarely any heavy rain and the prevailing north winds helps keep temperatures around 30°C (86°F) daily.  If you enjoy sailing or windsurfing, this is a great time to visit.

As with elsewhere in Thailand, temperatures rise between March and may, hitting a maximum of 35°C  (95°F) .  Rainfall though is still relatively low and sea breezes keep humidity levels to a more bearable level on the islands than on the mainland.  From June onward heavy rain showers are a daily occurrence.  The monsoon rains arrive in August and September.  When overnight thunderstorms are commonplace and humidity rises accordingly. 

The rainfall around Samui and Koh Pa-Ngan peaks during October and November.  These islands often receive the remnants of tropical storms that originate in the Philippines and pass south of Cambodia, bypassing Koh Chang and Koh Kood into the southern Gulf of Thailand.  Seas can be rough and there can be prolonged rainy days during this time. 

There are couple of exceptions to the generalizations above.  One of the wettest areas of Thailand is the coast in Trat province, near the Cambodian border.  Koh Chang and Koh Kood have great weather from November through until April with the mercury hovering around 27 – 30°C (82 – 88°F) most days.  And this is followed by a long rainy season lasting from May until October.  Although it doesn’t rain all day every day. During daylight hours it can often be dry with light cloud cover and some sunshine. But there is often prolonged heavy rain overnight.   

Conversely, the corner of  the Gulf coast centered around Pattaya, Koh Samet and Rayong is one of the driest areas of the country.  This area follows the same climate pattern as the rest of the area but the amount of rainfall is much lower.   It’s one of the driest areas of the country. 

Floods in Bangkok

What’s the weather like in Thailand in January?

 

January Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 20 32 11
Chiang Mai 13 29 8
Phuket 22 32 42
Hua Hin 21 31 13
Koh Samui 24 29 144

The best places to visit in Thailand in January

A great time to visit northern, central and eastern Thailand.  Plenty of sunshine, not too hot and virtually no rain.   Although if you are heading up north, and especially if you are going trekking, pack some warmer clothes as it can get chilly in the hills at night and early morning.  

As the chart above shows beach lovers should expect some rain if they;re heading to Phuket or Samui.  There can be quite a few wet days on Samui in January.  So it wouldn’t be my first choice for a beach.   Try Koh Chang, Koh Mak or Koh Kood in the east of Thailand and you’ll be virtually guaranteed sunshine and calm seas.  Or the Andaman islands, where you still might get a shower or two. 

January is also a very busy month for tourists across Thailand.  So be sure to book accommodation in advance and don’t expect to find good deals on rooms. 

What’s the weather like in Thailand in February?

 

February Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 33 28
Chiang Mai 14 32 6
Phuket 22 31 14
Hua Hin 23 31 19
Koh Samui 25 30 33

The best places to visit in Thailand in February

Bangkok and Central Thailand are hotter than the rest of the country, but unbearable so. It’s also a very dry month.  So it’s a good time of year to visit the city’s temples and outdoor attractions.

Up north, the temperatures are still cool early morning and in the evening.  And the climate is more like the European summer.  The burning season hasn’t yet begun, especially earlier in the month,  making it a great time to visit Chiang Mai, Pai or Chiang Rai. 

The weather in Phuket, Krabi, Koh phi-phi and Koh Lanta is at its best in February.  Plenty of sunshine and calm, clear seas.  Likewise on Koh Samui, the winter rains will have subsided and February has some great weather.  Perfect for a winter beach vacation.

In the east of Thailand, you can expect plenty of sunshine and very little rain everywhere from Pattaya to Koh Samet to the islands of Koh Chang, Koh Mak and Koh Kood in Trat province.  The temperatures will also be pleasant, with a maximum of 30°C (88°F).

What’s the weather like in Thailand in March?

 

March Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 34 31
Chiang Mai 19 35 17
Phuket 23 34 75
Hua Hin 24 32 28
Koh Samui 26 31 65

The best places to visit in Thailand in March

Compared to February March is always a little hotter and a little wetter pretty much everywhere in Thailand.  Overall it’s still a good month to visit most areas but heat and also pollution need to be taken into account.

The north of Thailand starts to get very hot and that coupled with the annual burning season means that March isn’t an ideal month for exploring the hill country around Chiang Mai, Chiang Rai or Pai.  It’s far better to visit in February or wait a couple of months until May.

Bangkok will feel uncomfortably hot and humid.  It always feels even hotter in the city as the concrete absorbs and radiates heat.  Far better to limit your time there and head to one of the coastal areas where the climate always feels cooler due to sea breezes. 

March is still a great time for beach lovers.  Across the south of Thailand visitors can expect a few rainy days during March, but nothing that would ruin a holiday.  And on the eastern side of the Gulf, there’s plenty of sunshine, and virtually no rain, to be found around the Koh Chang area. 

What’s the weather like in Thailand in April?

 

April Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 35 72
Chiang Mai 22 36 45
Phuket 24 34 157
Hua Hin 25 33 35
Koh Samui 26 32 86

The best places to visit in Thailand in April

April is the time of Songkran, Thai New Year.  A Buddhist holiday which is observed by massive water fights across the country.  And many visitors are happy to get into the spirit of things as the heat can be intense.  Chiang Mai is a very popular spot for both Thai and western tourists in April.  If you want to experience the largest celebration of the year, Songkran in Chiang Mai should be on your ‘to do’ list.

The ancient cities of Ayuttaya and Sukhothai are also well worth visiting at Songkran for their more serene, traditional festivities which are centered around the temple complexes.  

Elsewhere in the country the rain is becoming more prevalent and days are often a mix of cloud and sunshine with some thunderstorms. Although the heaviest rain is often overnight.  So bad weather is unlikely to spoil anyone’s vacation. 

Hua Hin is usually a safe bet for visitors who want to maximize their sunbathing time with less rain than the southern islands. 

Songkran in Chiang Mai

What’s the weather like in Thailand in May?

 

May Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 34 190
Chiang Mai 23 34 153
Phuket 25 32 345
Hua Hin 25 33 105
Koh Samui 26 33 158

The best places to visit in Thailand in May

May sees the end of the high season.  In most regions the rain intensifies as the month goes on.  But in tourist destinations all the restaurants and tour operators will be open and running at least for the first half of the month. 

The sea will begin to get rougher around coast areas and the days can often be a mix of everything from blue skies and sunshine to a thunderstorm.  The weather can be very unpredictable from day to day.

However, it’s a good time to visit the north of the country.  The burning season will have finished.  The first rains will have started to revitalize the jungle and the skies will be clear.  There will be fewer tourists visiting, so room rates will come down and savvy travelers can get some great deals whilst still enjoying some good weather. 

What’s the weather like in Thailand in June?

 

June Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 26 34 180
Chiang Mai 23 33 133
Phuket 25 31 260
Hua Hin 26 33 80
Koh Samui 24 30 118

The best places to visit in Thailand in June

During June the best areas of Thailand to visit are the western Gulf Coast and nearby islands.  These areas get the least amount of rain. 

If you want an easy drive from Bangkok, Cha-Am or Hua Hin are ideal choices.  Or head down to the islands of Samui, Koh Tao or Koh Phi-phi. You’ll still get some rainy days but the monthly rainfall is much lower than the Andaman coast, the north of Thailand or the east, near the Cambodian border.  Koh Chang can be very wet in June.

Northern Thailand is also worth visiting in June, it’s the driest of the rainy season months.  Following May’s rains, the rivers and waterfalls will be at their best. a great destination to visit in June, as the heavy rains of May taper off a little.

However, you can still enjoy the lush beauty of Thailand in the rainy reason, with green and verdant hills and full and powerful rivers and waterfalls. The average temperature in this month in Northern Thailand is 28°C (82°F).

What’s the weather like in Thailand in July?

 

July Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 33 185
Chiang Mai 23 32 150
Phuket 23 30 270
Hua Hin 25 33 95
Koh Samui 24 29 110

The best places to visit in Thailand in July

Very similar to June.  The weather will be a lottery where ever you go.  But for the best chance of getting more sunshine than rain head to the western gulf coast and nearby islands.  Hua Hin and Samui are popular spots at this time of year. 

Whereas it’s best to avoid the Phuket area and Koh Chang / Koh Kood area which can both be very wet.  If you are visiting those areas beware of rip currents and rough seas.  Overall this isn’t the time of year for a scuba diving holiday in Thailand.

The north of Thailand will feel cooler than the indicated temperatures and there are often a lot of overcast, cloudy days.  Rain can be in the form of persistent drizzle.  For most visitors a short thunderstorm is preferable as although that means more rainfall, the sky also clears quickly and sunshine returns.

What’s the weather like in Thailand in August?

 

August Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 26 33 170
Chiang Mai 23 31 200
Phuket 23 30 280
Hua Hin 25 33 90
Koh Samui 24 30 100

The best places to visit in Thailand in August

A good month to visit anywhere in the north of Thailand.  Lush jungles, very little rain, clear skies and not too many visitors. 

There is a lot of rain but this is often in big storms that pass over the area, depositing a large amount of rain in a single night.  Be prepared for strong winds.  This can be followed by a week of sunny, dry weather.

Bangkok on the other hand will be cloudy and overcast on many days.  It’s hard to plan outdoor activities at this time of year as downpours are frequent throughout the day.  The same applies across central and eastern Thailand.

At this time of year the best strategy is not to book all accommodation in advance and to be flexible with your plans.  It’s easy to take a budget flight from Bangkok to all corners of the Kingdom and there are always good deals on hotel rooms to be found.  Keep an eye on the weather forecasts and plan accordingly once you are in the country.  Then you’ll be able to follow the sunshine.

What’s the weather like in Thailand in September?

 

September Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 32 220
Chiang Mai 23 32 190
Phuket 24 30 400
Hua Hin 25 33 100
Koh Samui 25 31 190

The best places to visit in Thailand in September

As with the previous couple of months, Samui, Koh Pa-Ngan plus the mainland resort towns of Hua Hin and Cha-Am are the best options for visitors looking for sunshine and a beach holiday. 

September is the wettest month of the year.  In many areas the ground is saturated, rivers can easily flood and landslides are common in mountainous areas.  The sea is also likely to be rough. 

So September isn’t the time to visit Thailand if you are a ‘typical tourist’.  But for people who want to chill out, enjoy peace and quiet and simply get away from it all then it can be an ideal time to visit. 

Resort areas will have a very different, more laid back atmosphere.  Business owners aren’t rushed off their feet and aren’t thinking of making as much money as possible.  The locals have more time to sit and talk.  So for anyone who wants to experience the people, more than the place, it’s a good time to visit Thailand. 

Sea of cloud in northern Thailand

What’s the weather like in Thailand in October?

 

October Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 25 32 190
Chiang Mai 22 31 120
Phuket 24 31 280
Hua Hin 24 31 200
Koh Samui 24 30 290

The best places to visit in Thailand in October

The worst of the rainy season is over in many areas of Thailand by mid to late October and the blue skies make a welcome return.  The main change for beach lovers is that the best islands to visit are no longer those in the southern Gulf. 

The weather on Koh Samui and Koh Pan Ngan begins to deteriorate at this time of year, just as it improves dramatically in the Phuket, Koh Lanta and Krabi areas.  Over in the east of Thailand visitors to Koh Chang will experience plenty of bright, dry days with calm seas.   With the weather often being as good as during high season, but without the high numbers of visitors.

Air quality is usually excellent across Thailand at this time of year, it’s an ideal time to visit for photographers.  With more sunny days and still plenty of life in the waterfalls and rivers nationwide. 

October is also a cheap month to visit.  Hotels are always discounted and many airlines have good deals on flights prior to the high season beginning. 

What’s the weather like in Thailand in November?

 

November Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 23 32 46
Chiang Mai 19 30 51
Phuket 23 31 200
Hua Hin 24 30 140
Koh Samui 24 30 420

The best places to visit in Thailand in November

November heralds the start of the cooler, dry season.  The prevailing winds will change and cooler air is brought down from the north.  This is a great time of year for anyone who is into sailing to visit.  You’re guaranteed good winds.  

The central, eastern and northern areas of the country will all be fairly dry.  With sunshine virtually every day and very little chance of rain.  Skies will still be bright and clear and the air quality will be great.

High Season doesn’t really kick in until December, so in many areas although the number of visitors will increase as the month goes on, beaches, temples and tourist attractions won’t feel too crowded or busy.

The good weather in most regions, coupled with not too many visitors makes November one of the best months to visit.  Especially as flights to Thailand are still relatively inexpensive at this time of year. Relax, take in the sun and have a great vacation.

I should also mention that this is the worst time of year to visit Koh Samui and neighboring islands.  As November is a very wet month and storms are frequent.  It’s far better to visit Phuket or Koh Lanta where there’s less rainfall.  Or head to Koh Chang where there’s often virtually no rain in November.  

What’s the weather like in Thailand in December?

 

November Averages Min. Temp. (ºC) Max. Temp. (ºC)  Rainfall (mm)
Bangkok 23 32 46
Chiang Mai 19 30 51
Phuket 23 31 200
Hua Hin 24 30 140
Koh Samui 24 30 420

The best places to visit in Thailand in December

December is a very popular time to visit Thailand, the weather is pleasant and overall rainfall is low. The only area where the weather is often bad in the southern gulf islands around Koh Samui.  If you are planning an island vacation look more towards Koh Lanta and Koh Lipe areas or the east of Thailand and Koh Chang, Koh Mak or Koh Kood.

Skies will also be clear and bright across most of the country.  In the north, the temperature will dip and it’s a great time to see ‘seas of clouds’ in the valleys.  When air near the ground is cooler than the air above it mist forms and a this temperature inversion gives rise to the effect of a sea of fog or cloud sweeping across the nearby area. 

Of course you can only be appreciated if you are at a relatively high altitude.  The sky will be bright blue and you can gaze across the sea of clouds with the mountain peaks rising out of it.  Touring the north of Thailand by car is great at this time of year.  especially in the more remote areas such as Pai which has very few visitors but is more scenic than Chiang Mai or Pai. 

As temperatures and humidity are moderate (for Thailand) in December, it is also a  good month for visiting outdoor attractions such as the temple complexes in Ayuttaya or Sukhothai or  exploring National Parks.  

Christmas isn’t a national holiday in Thailand.  It’s a normal working day.  Shops, malls and restaurants around the country put up decorations, trees and lights.  Thais love a good party and Christmas is the ideal excuse to have one, whether you are Buddhist or Christian.  

Visitors to Thailand can choose how much Christmas they want.  If you want to avoid it entirely then that’s easy to do.  If you want to have a full western Christmas complete with roast turkey dinner and carols, then you can easily find that too.  

When is the Best (and Worst) Time To Visit Bangkok?

The weather isn’t as important to visitors staying in Bangkok.  As you’re unlikely to be spending your days sunbathing if you’re staying in the city.  All temples and attractions are open year round and if there is any rain then it’s easy to find cover wherever you go. 

But April and May are the hottest months with an average daily temperature of 31°C (88°F).  The sunniest but also coolest is December at 26°C (79°F) . If you are visiting in September, pack an umbrella, there’s an average of 220mm of rain.

Average Monthly High and Low Temperatures in Bangkok

Daily High and Low Graph on Monthly High & Low Temperatures in Bangkok

Average Monthly Rainfall in Bangkok

When is the Best (and Worst) Time To Visit Phuket?

March is the hottest month in Phuket and December is,on average, the coldest.  Although it isn’t actually ‘cold’ with a daily average of 27°C (81°F).  Whilst many areas of the country are beginning to cloud over in April, it’s Phuket’s sunniest month with around 9 hours / day of sunshine. 

And September is the wettest when visitors can expect around 400mm of rain during the month.   But throughout the rainy low season, visitors need to the heed warnings of rip currents on the west coast beaches.  If red flags are flying on the beaches, don’t swim in the sea.  Stick to the hotel pool. 

Average Monthly High and Low Temperatures in Phuket

Daily High and Low Graph on Monthly High & Low Temperatures in Bangkok

Average Monthly Rainfall in Phuket

Graph of average monthly rainfall in Phuket

When is the Best (and Worst) Time To Visit Chiang Mai?

The north of Thailand has the widest variation in temperatures.  April is the hottest month in Chang Mai, at around 30°C (86°F).  December is the coolest with an average high in the low 20s Celsius. (Barely 70°F) But the skies are clear with loads of sunshine and hardly any rain.  November through February is a great time to take advantage of the cool , dry climate and great visibility.  An ideal time for trekking. 

March and April are the smoggiest, this isn’t reflected in climate data.  So you’ll need to check the AQI readings ( See https://aqicn.org/city/chiang-mai/ ).  Most years Chiang Mai is among the most polluted cities in the world at this time of year.  Something you won’t see mentioned in most travel guides.  August and September are the wettest months of the year.  Although at 200mm / month, this is less than many areas of Thailand at this time of year. 

Average Monthly High and Low Temperatures in Chiang Mai

Daily High and Low Graph on Monthly High & Low Temperatures in Chiang Mai

Average Monthly Rainfall in Chiang Mai

Graph of average monthly rainfall in Chiang Mai

When is the Best (and Worst) Time To Visit Koh Samui?

As usual the temperature graph doesn’t tell us anything we don’t already know.   It’s going to be pretty warm regardless of when you visit Samui. Average daily highs are between 26 – 33°C (80 – 93°F) year round.

The driest time of year is from December to March and is the busiest time of year on the island. But visitor’s should note that Samui does receive more rain than Phuket at this time – especially in December and January.  There again, during the hot season temperatures remain pleasant as the island is located well out into the ocean. And as the rain starts to fall heavily across most of Thailand in May, Samui receives much less than Phuket and other beach destinations.

If you’re thinking of visiting in July and August then Samui is one of the best places to go in Thailand at that time of year.  You will avoid the worst of the rain and get plenty of sunshine.

It’s a different story towards the end of the year.  Islands on the eastern side of the Gulf, such as Koh Chang and Koh Kood will be basking in sunshine whereas from October through until mid- December is probably the worst time of year to visit weather-wise. 

Average Monthly High and Low Temperatures on Koh Samui

Monthly High and Low Graph on Monthly High & Low Temperatures on Koh Samui

Average Monthly Rainfall on Koh Samui

Graph of average monthly rainfall on Koh Samui

When is the Best (and Worst) Time To Visit Hua Hin?

The hottest months in Hua Hin are April and May with highs around 32-33°C (89 – 94°F).  December and january are the coolest.  Despite being relatively close to Bangkok, Hua Hin receives much less rain that the capital. Especially during the European summer holiday months of June, July and August. 

If you’re thinking of visiting at that time then Hua Hin is a good spot to get some sunshine within easy reach of Bangkok.  October and November receive the highest rainfall, which is still only around 200mm / month.  This is far lower than the wettest months in Phuket or Samui, for example. 

The flipside is that, on the rare occasions when the town does experience much heavier rain than normal, there can be floods. As the drainage system isn’t designed to cope with extreme weather.

Average Monthly High and Low Temperatures in Hua Hin

Monthly High and Low Graph on Monthly High & Low Temperatures in Hua Hin

Average Monthly Rainfall in Hua Hin

Graph of average monthly rainfall in Hua Hin

The Worst Time to Visit Thailand

There isn’t really a bad time to visit Thailand.  Regardless of the weather they will always be markets, temples, great food and nightlife.  But there are times of year when it’s better to stick to certain areas of the country.

If you’re a sun worshiper and are planning your trip to Thailand with the aim of returning home with a golden brown tan, then it’s best to skip June to October.  Or if that’s the only time you can travel, Koh Samui would be the best option. 

During this time the north of Thailand can see flash floods and any outdoor activities will often involve getting wet and muddy.  And if you’re in Bangkok be prepared for late afternoon downpours that cause traffic jams plus delays on the skytrain and subway to to heavy rain and an increased number of passengers.

The upside of travelling in the low (rainy) season is that you’ll get some great deals on hotels and will avoid crowds of fellow tourists.  Plus, although it can be very wet, a lot of the rain is overnight.  So many for many green season visitors the price savings override the lack of guaranteed sunshine. 

Koh Chang and the Andaman coast are best avoided in June and July when they often experience heavy rain and storms.  Even when the sun is shining the sea can be too rough to swim in safely. 

At the other extreme, certain areas can be too hot and dry.  Central and north-eastern Thailand can be brutally hot from march to May.  With temperatures reaching 40°C (105°F) or more.  That coupled with the dusty dry air, the result of very little rain for the preceding 4 or 5 months makes the climate very uncomfortable.  Therefore, anyone planning a trip to the ancient cities of Ayuttaya or Sukhothai; or to Kanchanaburi, for example, should bring plenty of Factor 50 sunblock. 

Stormy weather in Thailand

Bad Air Quality in Thailand

Man made pollution is another aspect that now , unfortunately, has to be considered when planning a holiday to Thailand.  The air quality doesn’t merit a mention on many websites, which focus solely on the temperature and rainfall.   Visitors with respiratory problems or families travelling with young children, should research the air quality in destinations they are planning on visiting.

The burning Season in Chiang Mai, and across most of northern Thailand, takes place every year.  This lasts for a couple of months from mid-February until Thai New Year in mid-April.  The cause is farmers clearing fields for new crops to be planted.  This is made worse by fires getting out of control and then spreading across hillsides.  Some days the pollution isn’t too bad, on others visibility can literally only be a few hundred metres.  It often depends on the direction of the prevailing winds.  Many expats who live in the north opt to leave their homes and head south for a couple of months to avoid the choking smoke filled air

Whilst the burning season in the north has long been a cause of pollution, more recently sugar cane farming has been causing equally bad pollution across central and eastern Thailand.  The past decade has seen a boom in sugar cane production in Thailand and also over the border in Cambodia. This is mainly due to increased demand for ethanol.  Which is added to gasoline to make ‘green’ fuels for consumers in Europe.  The downside is the negative effects the green fuel has on the environment where it is grown.  In Cambodia the E.U. subsidizes sugar can production.  

There are three ways to strip leaves from sugar cane – by hand with a knife; by machine or by burning.  By had takes too lang.  Machines are too expensive.  Burning is quick and easy.  So every year in January and February, farmers in the sugar cane growing areas of central Thailand and in Cambodia burn their fields.  The result is these areas and neighboring provinces are often covered in a smokey haze.  Again, how severe the haze is and which areas are worst affected, depends on the wind direction. 

So, When Should You Visit? 

That depends on your priorities. Ask yourself, “What is most important for me?

If it’s cooler temperatures and the best chance of getting plenty of sunshine and avoiding rain, then visit during the Cool season.

If you want to save money and get the best deals on flights and hotel rooms then the Rainy season is probably your best choice.

Of if the beaches in the south of Thailand are a priority or you want to take in the Thai New year celebrations, then visit during the Hot season