Cambodia's climate is driven by monsoons. From November to April, there's dry and cool northeastern wind which makes the air dry and more pleasant. From May to October, there's southwestern wet and strong wind causing heavy rains and high humidity. The annual biggest  rainfall of 5000mm is found in the seaward slope of the southwestern mountain range while in the central plains it's only 1400mm per annum.

Daily temperature can be over 40°C in April when it's hottest and about 30°C in January when it's coolest. The lowest temperature has never been lower than 10°C and the common temperature in hot season is mostly around 33- 35°C.