What is the overall climate: is it extremely hot or cold, wet or dry, at any time of year, for example?
Friggin' hot. Last year Hermosillo had one day when it was the hottest place on earth. It's over 100 degrees anywhere from 8-10 months a year. It's barely chilly in the "winter" and it's quite lovely for several months. Last year's summer seemed to be a lot worse, and I felt my kids were never able to leave the house because it was so hot. - Aug 2015
The majority of the year is lovely, but when summer hits, watch out. The temps rise into the 100-120 range from about June into October. I can count the number of days it has rained here on my fingers. During the wet months- July and August, when it does rain it is a deluge. It is true that you get used to it. - Apr 2013
Summer temperatures are extreme. They can often be between 115 and 120 degrees Fahrenheit from 1:00-6:00 PM during the worst of the summer heat. Winter temps are very pleasant and are usually in the 70s during the day and 50s at night. During the coldest periods of the year (Jan-Feb), temps at night may approach freezing. - Dec 2009
Flat out hot from late spring through fall (I've seen 120° F plenty of times) so be prepared. Most homes and businesses are air conditioned, but your car will get really, really hot when it's left outside in the summer (even in the shade). In summer, the desireability of parking spots is determined more by the availability of shade than by proximity to the door you will actually walk through. There are beautiful winters, with plenty of sunshine and daytime highs ranging from the low 50's to the mid 80's (F) for most of the winter and early spring. Essentially, it's beach weather all winter if you're used to U.S., Canadian, or European temperatures (actually, the ocean may be a little too warm for you in the summer if you're not used to the warm waters of the Sea of Cortez). Evenings and early mornings can be realtively cold in winter (temperatures can drop into the mid 20's F, though lows in the 40's are far more common) and few homes and buildings have heating. - Feb 2008