If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Valle de San Jose: The hottest months are usually February and January, with an average temperature of 20°C, while the coldest months are November and December, with an average of 19°C. The rainiest months in Valle de San Jose are May, October, August and April, with each month seeing an average of 562 mm of rainfall.