Tucson's high hit 84 degrees Thursday, easily breaking the high for the date of 81 degrees, set in 1969.
The National Weather Service said the high was broken at 12:50 p.m.
The high mark was also just 1 degree shy of the all-time December high temperature, the NWS said.
The warm weather will give way to much colder temperatures and the chance of rain Saturday.
Highs on Saturday and Sunday will be in the 50s to near 60. Overnight lows will drop into the 30s for the weekend and continuing into next week.
There is also a good chance for rain in the Tucson area on Saturday.
