If you're hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Coatzacoalcos: The hottest months are usually May and April, with an average temperature of 28°C, while the coldest months are January and February, with an average of 23°C. The rainiest months in Coatzacoalcos are September, August, July and October, with each month seeing an average of 332 mm of rainfall.