Taking into account the local weather in San Andrés is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually May and April with an average temp of 80°F, while the coldest months are January and February with an average of 70°F. The rainiest months in San Andrés are October, September, November, and August, with each month seeing an average of 14 inches of rainfall.