Mexico has a tropical climate and temperatures are more dependent on the altitude than the time of the year, ranging between twenty to thirty degrees from the highlands to the coast. There are only two seasons: the rainy season and dry season. The dry season lasts from mid November to mid May and the rainy season lasts from mid May to mid-November. In the rainy season everything is in full bloom and everything is much greener. The mornings are pretty bright, then in the afternoon a storm can come, cooling everything down.
You can visit the area throughout the year.