The weather is always good. Well, almost. Although the lower Baja is surrounded by water, its humidity is low, while its temperatures are comfortable, year round. There are variations (see below), but in general there is not a bad time of year to visit Los Cabos.
Temperatures through the winter are typically between 60’s (night) and 80’s (day), and in summer ten or so degrees warmer. Water temperature lags air temperature in the annual cycle, so the water is warmest from July through October (up into the mid 80’s), and coolest in January and February (plummets into the low 70’s for a while). There is a noticeable difference between Cabo San Lucas, which is exposed directly to the Pacific’s cooling breezes, and San Jose del Cabo, which is not – as much as ten degrees at times.
Also, humidity changes over the year, highest in late summer and fall (July through October), and at desert levels the rest of the year. Those visiting from the American southeast will laugh at the summer humidity, though, and give thanks that they’re not at home. Also seasonal is the threat of storms, which arises because of an increase in Pacific Ocean temperatures, and which is highest in those same months of July through October. Eastern Pacific storms usually form up south of the Baja off Mexico’s west coast and then meander northward as they take form, usually heading out to sea and breaking up before reaching the peninsula but occasionally bringing clouds and, infrequently, rain and wind. The threat of hurricanes, fully developed storms, is therefore part of this pattern, and is generally low but nonetheless real.
To have a look at current weather if you’re contemplating a trip, weather.com is a good choice, and the national hurricane center keeps track of all storm activity that could evolve into weather for Los Cabos.