Tucson has some of the most variable weather in the west. In summer, it's so hot it takes your breath away, and by winter, you may find snow on the ground. If you're planning a visit, check our weather and climate page for annual averages and current conditions.
And no matter how earnestly they say it, don't believe those Tusconians who say "but it's a d-r-y heat." If you're not used to it, it's just plain hot.