Santa Gertrudis, Mexico offers 1 beach perfect for sunbathing, surfing, swimming, and more. Santa Gertrudis, Coahuila, Mexico, is known for the Santa Gertrudis Military Camp and its historical significance in the Mexican Revolution. The best time to travel to Santa Gertrudis, Mexico, is from November to April, with average air temperatures around 75°F (24°C) and water temperatures near 78°F (26°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!