Weather can make or break a road trip, so here's some data about year-round temperatures in Sahagún to help you plan yours: The hottest months are usually February and March, with an average temperature of 28°C, while the coldest months are November and December, with an average of 26°C. The rainiest months in Sahagún are May, August, July and June, with each month seeing an average of 292 mm of rainfall.