If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Kampong Cham: The hottest months are usually March and April, with an average temperature of 29°C, while the coldest months are January and December, with an average of 27°C. The rainiest months in Kampong Cham are September, October, August and July, with each month seeing an average of 280 mm of rainfall.