If you're hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Bo Nok: 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 79°F. The rainiest months in Bo Nok are September, October, July, and May, with each month seeing an average of 10 inches of rainfall.