Weather is probably a major factor when you plan your trip to Isla Holbox, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and July with an average temp of 83°F, while the coldest months are January and February with an average of 76°F. The rainiest months in Isla Holbox are June, September, October, and August, with each month seeing an average of 7 inches of rainfall.