While the favorable Thailand weather was probably a factor in your decision to vacation in the "land of smiles" some background information regarding the climate is very useful if you are not accustomed to excessive heat.
If you spend enough time in Thailand you will hear a common Thai phrase spoken which is 'ron mak mak' which means the weather is very hot. With blue skies, year round sunshine and consistently high daily temperatures, it is little wonder Thailand has become one of the world's most visited countries.
However, if you are planning a vacation to Bangkok, be aware that if you visit during the Thai summer, temperatures will hover close to the 40 degree mark; it can prove to be a very hot and humid destination.
As my Thai brother-in-law likes to tell me, Thailand weather is either hot or very hot so if you don't wish to be sweltering on your Thailand vacation read along for some useful tips on where and when to visit Thailand.
Thailand is divided into six geographical regions and the weather does vary some what between these regions (see best places to visit for more information).
THAILAND DURING CHRISTMAS
In my opinion the best time to visit Thailand is between the months of November to February, during which time Thailand weather is at it's best being both the coolest and driest time of the year. If you do happen to visit Thailand during these months, I would highly recommend a visit to Bangkok during the December Christmas period.
Despite Thailand being a Buddhist country they still provide an impressive Christmas light display outside of the major shopping malls including Siam Paragon and MBK. Regardless of which time of the year you visit Thailand I suggest you keep water and sunscreen in your bag at all times whenever you leave your hotel because Thailand weather is hot.
southern Thailand is situated only 15 degrees north of the equator the weather
can best be described as
a tropical climate with a monsoon season. It is useful to remember that the
northern provinces (including Chiang Mai) are located further from the
equator and therefore usually have cooler daily temperatures than the
central and southern Thai provinces. The northern provinces are also less affected by the monsoon rains.
Thailand's daily temperatures are quite high (i.e. averaging 26-34 degrees centigrade all year with little variation in the south) as is their annual rainfall. From my experience visiting Thailand, the daily temperature can push towards 40 degree's particularly in Bangkok and Phuket during the hot summer months. The town of Phuket which is another popular tourist destination and located approximately 860 km south of Bangkok, is also extremely hot during the Thai summer probably due to it's closer proximity to the equator.
The hot season or summer period in Thailand (i.e. particularly noticeable in Bangkok and the southern provinces including Nahkon Si Thammarat) occurs between the months of March and June with average temperatures ranging between 28-34 degrees centigrade with humidity at around 75%. While shopping malls, hotels, taxi's and the BTS Skytrain are all air conditioned in Bangkok, the weather can still be extremely uncomfortable if you are not accustomed to a tropical climate.
Hence, if you are planning to visit Thailand during these summer months it would be preferable to visit the north if hot and humid weather is not your idea of a relaxing holiday.
The hot Thailand weather correlates with the most celebrated Thai festival known as Songkran. This festival is apparently based upon the suns shift from one zodiac to another, or the commencement of a new solar year. In real terms though, this Thailand water festival is celebrated by people wetting each other with water pistols and buckets of cold water, so if you are visiting Thailand during April enjoy the fun.
Thailand weather does have a cooler season (i.e. most notable in the northern provinces including
Chiang Mai and Chiang Rai which receives cool monsoon based breezes) between the months of November and
February with daily temperatures averaging a more comfortable 26-28 degrees centigrade. However, in the mountainous northeastern province of Loei, night time temperatures can drop to zero during this cooler season.
Make no mistake, the weather is still hot in other places such as Bangkok and Phuket which maintain higher temperatures than in the north of Thailand during the cool season. Yet the lower temperatures do mean that the heat and humidity is not as oppressive as is the case during the summer months.
During these cooler months of the year, the weather in the north is mostly dry and because
of the cooler temperatures many Thai's and
overseas visitors choose the northern locations for their holidays. Also, the majority of the monsoon rain arrives earlier between the months of May to November.
The monsoon season differs in Thailand depending upon the geographical location and time of year. As a general guide the monsoon season is more prominent in the south than the north of the country, although it does vary again between the southeast and southwest of Thailand.
For example, in Phuket the monsoon rains arrive between the months of April until October, which is very similar to Bangkok's monsoon season.
However, in the southwest of Thailand at the popular tourist destination of Koh Samui the wet season is between the months of October to January. In the north as noted above, the rains arrive between the months of May to November.
In relation to annual rainfall, the southern provinces of Thailand receives around 2,400 millimetres, with the central and northern provinces receiving around 1,400 millimetres.