The prime time to go Los Cabos snorkeling is between September and November. That’s when the southerly swells drop off from the marine-rich Sea of Cortez coast around the town. Temperatures in the water remain high, but things become stiller in bays like Santa Maria and on the Cabo Pulmo reefs. If you don’t mind braving some chillier waters, you could also come in January, February, and March. They have arguably the best visibility and also add in the chance of seeing migrating whales.