Climatology
This page presents Thailand's climate context for the current climatology, 1991-2020, derived from observed, historical data. Information should be used to build a strong understanding of current climate conditions in order to appreciate future climate scenarios and projected change. You can visualize data for the current climatology through spatial variation, the seasonal cycle, or as a time series. Analysis is available for both annual and seasonal data. Data presentation defaults to national-scale aggregation, however sub-national data aggregations can be accessed by clicking within a country, on a sub-national unit. Other historical climatologies can be selected from the Time Period dropdown list.
Observed, historical data is produced by the Climatic Research Unit (CRU) of University of East Anglia. Data is presented at a 0.5º x 0.5º (50km x 50km) resolution.
Mean annual temperature has increased by 0.8°С per century since the 1950's. Thailand enjoys a tropical climate which is influenced by seasonal monsoon winds. The southwest monsoon (May) brings a stream of warm moist air from the Indian Ocean towards Thailand, causing abundant rain over the country, especially the mountainous regions. This phenomenon is intensified through the Inter-Tropical Convergence Zone (ITCZ) in the months of May to October and tropical cyclones which produce a large amount of rainfall. The northeast monsoon, starting in October, brings cold and dry air from the anticyclone in China over major parts of Thailand, especially the northern and northeastern parts which are located at higher latitude areas. In the south, the monsoon causes mild weather and abundant rain along the eastern coast. Mean annual rainfall is 1,200-4,500 mm, with lower totals on the leeward side and higher totals on the windward side. Mean temperature is 26.3°C in the north and 27.5°C in the southern and coastal areas.