Weather will likely play an important role when you plan your trip to San Fernando, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June with an average temp of 83°F, while the coldest months are January and February with an average of 80°F. The rainiest months in San Fernando are July, September, June, and October, with each month seeing an average of 13 inches of rainfall.