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 Khemarak Phoumin: The hottest months are usually April and March, with an average temperature of 27°C, while the coldest months are January and February, with an average of 26°C. The rainiest months in Khemarak Phoumin are July, September, August and June, with each month seeing an average of 577 mm of rainfall.