Mid November to May are the best months for regular sunshine and calm seas on Mexican beaches, whether it’s the Pacific Coast (west side) or Maya Riviera (east side).
Naturally July-August, Christmas and Easter seasons attract huge numbers of vacationers from both inside and outside the country, but the heat is on as well as overpowering humidity and the storm clouds are gathering. . .
The worst are the hottest and most humid months, August – September, with heavy rain, cloud, and an insect problem too.
However, note that during the winter months trips to higher altitude locations such as Mexico City may be very chilly.
August-November has the possibility of rough seas on the Pacific coast due to storms.
For diving off Baja California August – November is best, with warm, clear water.