If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Quetzaltenango: The hottest months are usually March and April, with an average temperature of 16°C, while the coldest months are January and December, with an average of 16°C. The rainiest months in Quetzaltenango are June, September, May and August, with each month seeing an average of 472 mm of rainfall.