Taking into account the local weather in Bethel is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually February and March with an average temp of 81°F, while the coldest months are August and September with an average of 76°F. The rainiest months in Bethel are April, March, January, and February, with each month seeing an average of 11 inches of rainfall.