Weather will likely play an important role when you plan your trip to San Antonio, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and April, with an average temperature of 27°C, while the coldest months are January and February, with an average of 24°C. The rainiest months in San Antonio are November, July, October and August, with each month seeing an average of 365 mm of rainfall.