The Weather in the Sea of Cortez can be variable. This area is subject to Northers, Westerly, occasionall rain etc. You pretty much have to check on the local weather. I like to use weather charts from NOAA--certainly available from the internet, but also one can recieve the same products with a radio like the Grundig YB 400 (I have seen them for sale at our local West Marine for $100)--and a decent antenna (long wire will work fine) and a program on the computer. There is a demodulator to acquire the radio audio output and allow the computer to read this. (We had dedicated weather fax machines on our larger boats--not something a C Dory would carry)--also most of the major resorts will have a weather report. Watch the local fishing boats. Remember that the Pangas are relitatively sea worthy and somewhat similar to a C Dory. There can be quite a bit of chop in the afternoon. We have seen winds in the 55 knot range at times, and with a fetch--you don't want to be in that.
One has to realize that the upper Sea of Cortez is not really tropical during the winter--and most of the cruising boats go to Mazatalan or South Baja. Even La Paz can be cooler than Cabo in the winter. The Further South you go the warmer the water and air temp. For example Cabo is currently in the mid 80's--Guaymas is in the mid 70's (air temp). Water temps are going to be in the mid 60's in mid Sea of Cortez--and not to the 70's until you get to the Southern part of Baja. On the outer coast of Baja (Pacific), typical weather is North Westerly building to 25 knots in the afternoons--and it is quite a thrash up the coast.
Some places you will find good launching ramps and marinas, other places you may be wise to hire a local who launches off the beach with a tractor. There was a very ambitious plan with marinas every 35 miles, a railroad or good highway to transport boats from South of Ensendea to the Sea of Cortez, and it didn't materalize. Some new marinas have been built. They are very nice--and more expensive. We generally prefer to anchor in off the older parts of town, and do our shopping in the central Mercado--but with an occasional visit to Sam's club or the SuperMercado!...In rural areas things are still very primitative--in the resort areas--very modern--sort of on the surface....