The Weather & the Water of Cabo & La Paz

What’s a one-word description of Baja diving? Variable. Water temperature and visibility vary dramatically. Two divers returning from the Baja only weeks apart can give such different reports that you have a difficult time believing they’ve been to the same destination.

In the southern part, the temperature of the upper 30' of water or so remains warm enough year-round to support tropicals and several varieties of hard coral. Below that depth, winter and spring water temperatures in the 50s and 60s freeze out the tropicals. From midsummer through November, water temperature is 80°F. or higher as deep as sport divers would care to go.

During spring and summer, the surface water temperature rises, of course, but the big change is the lowering of the thermocline. This is a complex and uneven process. During a June visit the thermocline was at 45-50'. Sometimes the change was gradual or of small magnitude, but on one dive we recorded a plunge of 16 degrees between the surface, at 76°, and a thick layer of 60° planktonic green gloom 50 feet down. Later in the season, the water is 80° all the way past 100'. (I’ve even recorded 84° water in October.)

Another seasonal variable is the plankton concentration. Sometimes the more plankton-rich waters can be observed as distinct layers and masses. During my June trip, visibility was generally 30-40'. Later in the summer, it’s usually 80-100' — part of the annual evolution of conditions that make the Cortez so dynamic, so productive, and so different from the constant Caribbean.

After the first of December, north winds often make diving difficult because of rough seas. By spring the thermocline is high and a 1/4" wetsuit is recommended (some sort of protection from jellyfish is recommended year-round). Tropical storms can occur during summer and fall, just as in the Caribbean. On average, they are most likely from mid-September to mid-October. La Paz and its waters tend to be somewhat protected.