Parts of the Tucson area were covered in snow Monday morning, but more snow is likely as temperatures dropped to below freezing overnight in much of the area.

Monday’s high was “extremely chilly and likely the coldest of the winter season,” officials said.

A severe freeze warning is in effect for western Pima County, including the Tucson metropolitan area and Tohono Oddam Nation from 11:00 pm Monday to 8:00 am Tuesday. Portions of Pinal County are also covered, and temperatures are forecast to drop below 32 degrees overnight for much of southern Arizona.

Temperature gauges could drop as low as 27 degrees early Tuesday morning, and snow levels could bottom out at about 2,000 feet, National Weather Service officials said.

“Another storm system will pass through Arizona today and will enhance shots of cold air and scattered rain and snow showers east of Tucson,” forecasters said. However, temperatures are expected to moderate and no precipitation is expected for the rest of this week and into next weekend.”

By Monday morning, about 2 inches of fresh snow had fallen on Mount Lemmon, with snow in the Sierra Vista and Bisbee, and snow in the Oro Valley and parts of the Catalina foothills. During the day, snow accumulated along Interstate 10 in the Wilcox area, prompting the NWS to caution drivers.

“Take steps now to protect your tender plants from the cold,” said the NWS. If there are sprinkler systems in the ground, they should be drained and above ground pipes should be covered to protect them from freezing.”