Weather will likely play an important role when you plan your trip to Santa Cruz de Mompox, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually February and March with an average temp of 84°F, while the coldest months are November and October with an average of 80°F. The rainiest months in Santa Cruz de Mompox are May, October, August, and September, with each month seeing an average of 14 inches of rainfall.