Frost Advisory Issued in California as States Brace for Arctic Blast

Frost advisories have been issued in California as most of the U.S. braces for an Arctic blast to produce cold and stormy weather over the Thanksgiving holiday weekend.

Forecasters from the National Weather Service (NWS) are predicting that November will end in unseasonably cold weather for the contiguous U.S. due to cold air being pushed southward from Arctic regions. Some states are expected to be hit with snowfall likely to impact travel, while subzero temperatures in other regions could expose residents to health hazards like frostbite.

Most areas of the country with typically warm climates will not be spared, with even some parts of Florida expected to experience freezing temperatures by the end of the weekend. In California’s San Francisco Bay Area, which is rarely exposed to freezing weather, frost was expected heading into Thanksgiving morning.

The San Francisco NWS office announced that a frost advisory was in effect from 10 p.m. Wednesday until 9 a.m. Thursday local time in the following areas: East Bay hills and valleys, the Salinas and Carmel valleys, Hollister, most of San Benito County and the Cholame Hills in southeast Monterey County, the North Bay interior mountains and valleys, and the eastern Santa Clara hills.

NWS San Francisco warned that the “cold conditions will be hazardous to sensitive populations such as unhoused individuals” and “can lead to hypothermia with prolonged exposure.” San Francisco and adjoining cities like Oakland and San Jose have some of the country’s largest homeless populations.

While the cold weather approached on Wednesday, the San Francisco Department of Homelessness and Supportive Housing announced that it would be implementing a new policy on December 10 to limit the amount of time that homeless families can spend in shelters.

A department spokesperson told CBS News Bay Area that the change was “intended to ensure that our family homelessness response system is more efficient and better able to meet the needs of families in our community.”

Newsweek reached out for comment to the office of San Francisco Mayor London Breed on Wednesday night.

The NWS office in Eureka, California, also issued a frost advisory effective from Wednesday night until Thursday morning in areas north of San Francisco, including the Humboldt coast, Del Norte interior, northern Humboldt interior and the Mendocino coast.

“Frost could harm sensitive outdoor vegetation,” the advisory says. “Sensitive outdoor plants may be killed if left uncovered. … Take steps now to protect tender plants from the cold.”

Unusually colder temperatures were expected in all of the lower 48 states, while extreme weather in areas of the country including the upper Plains, the upper Midwest and the Great Lakes threatened to shut down roads and potentially impede air travel just in time for Thanksgiving.

Regardless of the weather concerns, Thanksgiving travel is expected to be heavier than ever this year, with the AAA predicting that a record-breaking 80 million Americans will travel at least 50 miles this week.