Thailand can best be described as tropical and humid for the majority of the country during most of the year. The area of Thailand north of Bangkok has a climate determined by three seasons whilst the southern peninsular region of Thailand has only two.
In northern Thailand the seasons are clearly defined. Between November and May the weather is mostly dry, however this is broken up into the periods November to February and March to May. The later of these two periods has the higher relative temperatures as although the northeast monsoon does not directly effect the northern area of Thailand, it does cause cooling breezes from November to February.
The other northern season is from May to November and is dominated by the southwest monsoon, during which time rainfall in the north is at its heaviest.
The southern region of Thailand really has only two seasons -- the wet and the dry. These seasons do not run at the same time on both the east and west side of the peninsular. On the west coast the southwest monsoon brings rain and often heavy storms from April through to October, whilst on the east coast the most rain falls between September and December.
Overall the southern parts of Thailand get by far the most rain with around 2,400 millimetres every year, compared with the central and northern regions of Thailand, both of which get around 1,400 millimetres.
Generally speaking,the best time to visit Thailand is from November to February when the northeast monsoon is blowing cool, dry air which serves as a respite from the heat. During this cool season, the temperature ranges from 18 degrees centigrade to 32 degrees centigrade in Bangkok, while in northern and northeast Thailand, temperatures can get quite cool with morning temperatures as low as 8 degrees centigrade to 12 degrees centigrade with the occasional 20 degree day. Nights can be particularly chilly and at high altitudes the temperatures can and do drop below freezing.
The summer period, or hot and dry season, is from March to June. At this time temperatures in Bangkok average around 34 degrees centigrade, but can often reach 40 degrees centigrade with the humidity levels of 75%.
Try and avoid April, unless you plan to be permanently submerged in the ocean, because this is the hottest month across the country.
From July to October is the monsoonal season when most of Thailand's annual rainfall is accumulated. The humidity averages just under 90%, with temperatures averaging around 29 degrees centigrade in Bangkok.
The monsoons finish when the wind direction changes, bringing dry weather from the northeast. At best this season can be described as unpredictable and not the constant downpour of rain like you would expect. The middle months of this season may hold particularly heavy rains for the north of the country.
For more information, please refer to our Thai weather map -- an interactive map to the weather situation in Thailand with detailed monthly statistics on rainfall, minimum and maximum temperature and number of rainy days in a month. Or refer to our detailed climate charts and month by month Thailand weather coverage here.
Please find below some of the more frequently asked questions (FAQ) people have about travelling to Thailand. We've tried to answer all the most frequently asked questions, but if you have another query about Thailand, please try our Travelfish messageboard.
Is it possible to rent rooms or dormitories for long periods of time?
Rooms: is a fan room ok, or should I budget for air-con?
Should I take my own padlock for the door of my room while travelling in Thailand?
What should I do if a bag is stolen from my room or dormitory while travelling in Thailand?
What standard of acommodation can I expect for US$5?
Why are there so few dormitories in Thailand?
Can I drink the tap water in Thailand?
How can I avoid MSG in Thailand?
How do I avoid peanuts in Thailand?
I have a food allergy - will I cope?
Is there good vegetarian food in Thailand?
Is western food available in Thailand?
Are the ferries in Thailand safe?
Are the trains in Thailand safe?
Do they trains run on time?
Is it easy to hitch-hike in Thailand?
Is it easy to rent a car or motorcycle in Thailand?
Should I get a tourist minibus in Thailand?
What is Bangkok's bus system like?
Which is the better way to travel around Thailand - train or bus?
Are credit cards accepted in Thailand?
Are there ATMs in Thailand?
How can I have money sent to me in Thailand?
How can I send money out of Thailand?
Should I bring travellers cheques, credit/debit cards or cash to Thailand?
Should I tip in Thailand?
Are leeches a problem in Thailand?
Are legal drugs cheap in Thailand?
Do I need a prescription in Thailand?
Do I need malarial medication in Thailand?
General food and water precautions in Thailand
General health advice for Thailand
HIV/AIDS in Thailand
Is cholera a problem?
Is heatstroke a problem in Thailand?
Is medical care cheap in Thailand?
Is medical care in Thailand good?
Is rabies a problem in Thailand?
Schistosomiasis in Thailand?
Traveller's medical kit for travel in Thailand
What about dengue fever in Thailand?
Will I get diarrhoea in Thailand?
Are there many internet cafes in Thailand?
Can I travel with a laptop in Thailand?
Is there ADSL internet access in Thailand?
What is mobile phone coverage like in Thailand?
What is the voltage in Thailand?