The climate in Thailand

Thailand is divided into several climate zones. In the north, the cold air flowing from the Chinese highlands determines the weather. The west coast enjoys the sea air of the Indian Ocean and the east coast enjoys the south Chinese sea air.

Nationwide there are basically three seasons: Midsummer, hot midsummer and hot midsummer with rain. The rain is warm and often pleasant. Rarely does a shower last longer than three hours. The rest of the day it is again cheerful to sunny.

It is warm to hot all year round and invites those in the coastal regions to bathe in the open sea with average water temperatures of 28 degrees. Sweaters or even jackets are only needed in the evenings in the high altitudes in the north of the country.

Temperature records of the last 74 years

The hottest temperature measured from 1949 to January 2023 was reported by the Nakhon Sawan weather station. In May 2016, the record temperature of 43.7 °C was reported here. The hottest summer from July to September, based on all 15 weather stations in Thailand , was recorded in 1987 with an average temperature of 28.9 °C. This average temperature will normally be measured every four to six hours, thus also including the nights. Normally, this value is 28.1 degrees Celsius.

The coldest day in these 74 years was reported by the Phitsanulok weather station. Here the temperature dropped to 5.8 °C in January 2000. Phitsanulok lies at an altitude of 46 meters above sea level. The coldest winter (January to March) was in 1972 with an average temperature of 23.5 °C. In Thailand, it is usual to have about 3.4 degrees more at 26.9 °C for this three-month period.

The most precipitation fell in November 1969. With 44.4 mm per day, the Songkhla weather station recorded the highest monthly average of the last 74 years. Incidentally, the region with the most rainfall for the whole year is around Chanthaburi. The driest region is near Nakhon Ratchasima.

Long-term development of temperatures from 1979 - 2022

In contrast to single record values, long-term development cannot simply be brought about by all weather stations in the country. Both the number and the locations are constantly changing. An average value would give a distorted result. If several measuring stations in particularly cold mountain or coastal regions are added in one year, the average would decrease as a result of this alone. If a station fails during the summer or winter months, it does not provide any values and distorts the average again. The subsequent long-term development was therefore reduced to only 4 measuring points in order to have comparable data over as long a period as possible.

In the years 1979 to 2022, there were only these 4 weather stations in the whole country, which reported continuous temperature values (Udon Thani, Phitsanulok, Chanthaburi, Chumphon). From these weather reports, we have created a long-term development that shows the monthly average temperatures. The hottest month in this entire period was April 2016 at 31.6 °C. December 1999 was the coldest month with an average temperature of 22.5 °C.

The average annual temperature was about 27.6 °C in the years after 1979 and about 27.7 °C in the last years before 2022. So it has hardly changed at all in the past 44 years. This trend only applies to the selected 4 weather stations in Thailand. A considerably more comprehensive evaluation of global warming has been provided separately.

Data basis and methodology

The data from the individual measuring stations are based on the archives of the German Weather Service, individual values averaged and supplemented by own elements. In order to determine a representative national average, average values were first calculated for each part of the country, which were then summarized at the national level. Thus, if a disproportionate number of weather stations are located in a small area, their number does not affect the national average. There are 16 stations in Thailand itself. In 6 cases, neighboring but nearby weather stations were also used to obtain more accurate values.