Weather is probably a major factor when you plan your trip to San Gabriel, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually October and November, with an average temperature of 12°C, while the coldest months are August and July, with an average of 11°C. The rainiest months in San Gabriel are November, December, April and March, with each month seeing an average of 364 mm of rainfall.