Planning for the weather is a good way to make your trip to San Salvador el Seco relaxing and enjoyable, especially when you're splurging. The hottest months are usually April and May with an average temp of 64°F, while the coldest months are January and December with an average of 57°F. The rainiest months in San Salvador el Seco are September, June, August, and July, with each month seeing an average of 11 inches of rainfall.