If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in San Carlos City: The hottest months are usually May and June, with an average temperature of 28°C, while the coldest months are February and January, with an average of 26°C. The rainiest months in San Carlos City are July, October, June and December, with each month seeing an average of 276 mm of rainfall.