This page presents Cambodia'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. Data for specific coordinates can be downloaded for in the Data Download page.
Cambodia's climate is tropical, with high temperatures, and two distinct seasons: a monsoon-driven rainy season (May‐October) with south-westerly winds ushering in clouds and moisture that accounts for anywhere between 80-90% of the country’s annual precipitation, and a dry season (November-April), with cooler temperatures, particularly between November and January. Average temperatures are relatively uniform across the country, but are highest in the early summer months before the rainy season begins, when maximum temperatures often exceed 32°C. Temperatures remain between 25-27°C throughout the rest of the year. The wet season arrives with the summer monsoon, in May through November, bringing the heaviest rainfall to the southeast and northwest. The annual average rainfall is typically 1,400-2,000 mm with higher rates in the coastal and highland areas and lower rates in other inland regions. Inter‐annual variations in climate result from the El Niño Southern Oscillation, which influences the nature of the monsoons in the region. El Niño events generally bring warmer and drier than average winter conditions across Southeast Asia, while La Niña episodes bring cooler than average conditions
- Temperature increases have been observed, with an approximate increase of 0.18℃ per decade since the 1960s.
- Temperature increases have increased most rapidly during the country’s dry season (November to April), increasing by 0.20℃ to 0.23℃ per decade.
- Temperatures have increase during the rainy season (May to October), but not as significantly, with increases between 0.13℃ and 0.16℃ per decade.
- The number of ‘hot days’ in the country has increased over the last century, by as much as 46 days per year.
- While rainfall was observed to increase in some areas since the 1960s, no statistically significant changes were detected over the 20th century, either in terms of annual rainfall or extreme events.
- However, precipitation variability is linked to the El Niño Southern Oscillation phenomenon, with years of strong El Niño correlated with years of moderate and severe drought over the 20th century.