If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Sepang: The hottest months are usually April and May with an average temp of 82°F, while the coldest months are January and February with an average of 80°F. The rainiest months in Sepang are November, December, October, and April, with each month seeing an average of 12 inches of rainfall.