We have been there on cruises only three times. We went in late Jan, early Feb. Great weather, mid 80's and no rain. I think the rainy season is in the fall months. We will cruise there again and will book Jan,-Feb again. Enjoy!
You will find the weather outstang this time of the year. A friend of mine in Cabo told me that the Avg Temp there is 80 degrees! We loved the Elation join us on West-Coast chat to discuss any questions you might have 730 western Rix :-)
Stacy-My wife and I did a mexican riviera cruise in 5/97 and hit all of the cities you mentioned. Weather was georgeous the whole time. Into the low 80s' during the day and 60s' at night. No rain the entire trip. You may want to pick up the "Pacific Mexico Handbook" from Moon Travel Handbooks. They also have one just for Cabo. According to what I read, winter days are typically warm peaking at 80-85 degrees. Drops to 60-70 degrees at night. Few degrees difference north to south. Summers are warmer and wetter. Rain in the p.m. in July, Aug and September but sounds kind of like Hawaii where the rains don't last long and clear off by evening. Summer warms up maybe five degrees. We loved our "repositioning cruise" (this is where ships are being moved from the Caribbean to Alask to start the summer season) in May. Good price and a nice ship. (Sun Princess). Hope this was helpful.