Rain is frequent from June through September. Evenings can be quite cool in winter. In this region, proximity to the coast determines temperature and humidity. In summer, Gulf and Caribbean areas stay cooler due to trade winds, while interior jungles are humid, with higher temperatures. September and October sometimes bring overcast or rainy conditions.
Winters are very pleasant.
Somewhat humid, with warmer temperatures. In your quest for a good time on your vacation, your eating and drinking habits are often radically different than what you're used to back home. In addition, climate and altitude changes can throw your system off. Try not to go overboard your first night. Give your body a chance to acclimate.