Cambodia has a tropical climate which, like the rest of Southeast Asia, is dominated by monsoons, bringing in dry or wet weather. In summer, the southwest monsoon is drawn landward from the Indian Ocean and the Gulf of Thailand. These winds bring the rainy season from mid May to mid October. During the rest of the year (Winter and Spring) the northeast monsoon brings drier and cooler air. Just before the rainy season starts (April and early May) temperatures and humidity are high.
The southern part of the country receives more rain than the central and northern parts. In the monsoon season, in Koh Kong, Sihanoukville, and to a lesser extend Kampot, it can rain for days on end, which is etremely rare in other parts of Cambodia.
We even go as far as saying that the rainy season is actually a good time to visit Cambodia, except if you plan on heading for the coast (see the map). It almost never rains all day, again except for coastal areas and the islands. During the rainy season, Cambodia’s trees and forests grow lusciously and you’ll see the country in its glory shades of green.
The average annual temperature is around 25ºC with little variation throughout the year (annual minimum about 22ºC, annual maximum about 28ºC). However, just before the start of the rainy season, maximum temperatures may rise to more than 38ºC. January is the coolest month, April is the warmest.
Typhoons are rare
Typhoons and tropical cyclones that often devastate coastal Vietnam rarely cause damages in Cambodia. The total annual rainfall average is between 1000 and 1500 mm. The heaviest amounts of rain fall in the southern, coastal areas and in the mountainous northeast. In Phnom Penh and Seam Reap, it almost never rains all day, such a pattern would be exceptional. During the rainy season, it is normal to have a heavy thunderstorm of about one hour in late afternoon, while the rest of the day is sunny and dry. However, on the south coast it can rain days on end during the monsoon season.
Precipitation and Temperatures
Underneath you see charts of average annual precipitation and temperatures in Cambodia’s capital Phnom Penh. For actual weather conditions and an outlook for the next five days, we have an extensive weather page with forecasts for no less than 18 cities and towns in Cambodia. A different actual weather and forecast is on the Phnom Penh weather page.