We are booked for Feb 6th 2011. We have been 3 times. June, November, and Feb.
June was gloomy, overcast, and humid. (except Cabo was sunnier).
November was nice and warm, but Feb was just beautiful! .
We went in late March, early April, and the weather was perfect. The water was somewhat warm in Cabo, and warmer the farther South we went. Acapulco was HOT and HUMID. Only Cabo has the HOT and DRY (it's in the desert), the rest of the ports are in more humid areas...