Freeze Warning Today: Where It’s Active, What It Means, and How to Protect Your Home

A fresh round of freeze warnings is in effect today, Monday, December 1, 2025, with sub-freezing temperatures expected overnight into Tuesday for several interior valleys of Southern California (including parts of San Luis Obispo County and the Antelope Valley). Elsewhere, dense freezing fog reduced visibility this morning across sections of the Midwest, while pockets of freezing rain and snow created slick travel in parts of the northern Rockies and western Canada. If your area sits on the edge of any of these hazards, plan for a hard chill tonight and take quick steps to protect pipes, plants, and pets.

What a Freeze Warning Means

A freeze warning signals a high likelihood of temperatures at or below 32°F (0°C) for several hours—cold enough to damage unprotected plumbing and kill sensitive vegetation. In many regions, these alerts are issued only during the growing season, but early-winter cold snaps still trigger warnings when a first significant freeze threatens populated valleys and agricultural zones.

Related alerts you might see:

• Freeze Watch: A potential freeze in the next 24–36 hours.

• Frost Advisory: Frost likely; temperatures often 33–36°F with light winds that allow surface freezing.

• Winter Weather Advisory/Ice Alerts: Used for freezing rain, mixed precipitation, or snow that affects travel.

Where Freeze Alerts Are Active or Likely Tonight

• Southern California interior valleys: Late-night through early Tuesday, with lows dipping into the upper 20s in the coldest pockets. Radiational cooling under clear skies will enhance the chill.

• High deserts and wind-sheltered basins of the Southwest: Patchy freezes possible, especially where winds decouple after midnight.

• Midwest: The morning hazard leaned toward freezing fog, producing a thin glaze on bridges and untreated walkways. As skies clear, overnight lows near or below freezing return to rural low spots.

• Interior Northwest and western Canada: Snow bands and occasional freezing rain keep surfaces slick; clearing behind these systems can drop temperatures quickly after sunset.

(Local conditions vary; always follow your city or county’s latest alert details.)

Timeline: Monday Night Into Tuesday Morning

• 8 p.m.–12 a.m. (local): Rapid evening cooldown in valleys and basins; frost begins forming on exposed surfaces.

• 12 a.m.–8 a.m.: Coldest window. Light winds and clear skies favor a hard freeze in sheltered spots. Any lingering fog can deposit a delicate ice glaze.

• After 8 a.m.: Sun angle lifts temps above freezing; shaded areas and bridges may stay slick longer.

How To Prepare in 15 Minutes

Pipes & water:

• Open cabinet doors under sinks on exterior walls; let warm air circulate.

• Drip a cold-water faucet farthest from your main line to keep water moving.

• Disconnect garden hoses; cover outdoor spigots.

Plants & pets:

• Bring potted plants indoors or into a garage; cover tender ground plants with frost cloth (avoid plastic touching leaves).

• Bring pets inside; provide extra bedding for livestock and ensure unfrozen water access.

Vehicles & travel:

• Park off-street if possible to avoid overnight sprinklers and curb ice.

• Set an earlier alarm to scrape windshields; keep de-icer and a soft brush in the car.

• Expect black ice on bridges/overpasses; brake gently and increase following distance.

Home energy:

• Set thermostats to maintain a steady temperature; avoid deep overnight setbacks that can chill pipes.

• Check smoke/CO alarms if using fireplaces or space heaters; keep heaters three feet from anything combustible.

Agriculture and Landscaping Notes

• Citrus, avocados, and flowering ornamentals are at risk in cold basins; microsprinklers or wind machines are specialized tools—use only if you already operate them and know local guidelines.

• For home gardens, water soil lightly before sunset (not leaves); moist soil holds heat better than dry. Employ row covers or blankets supported by hoops so fabric doesn’t contact foliage.

Common Questions About Freeze Warnings

How cold and how long is enough to cause damage?
Multiple hours at or below 32°F can burst uninsulated pipes and blacken tender leaves. A brief dip to 31–32°F may only cause light tip burn; a hard freeze (≤28°F for several hours) can be far more destructive.

Why are some neighboring towns not under a warning?
Valleys, elevation, and wind make dramatic differences over short distances. A ridge with a light breeze may stay a few degrees warmer than a calm basin.

Do I still need to prepare if I live in an apartment?
Yes—interior plants on balconies, exterior plumbing on ground floors, and morning commute hazards still apply.

Looking Ahead (Next 24–48 Hours)

Expect a gradual warmup after sunrise Tuesday, but another clear, calm night could set up one more frosty start midweek in traditionally cold spots. As the broader storm track reloads, some regions will pivot from freeze hazards to mid-week rain or mountain snow. Keep an eye on fresh advisories this afternoon in case your local office extends or upgrades alerts.

If you’re in or near a freeze warning today, protect pipes, plants, and pets before bedtime, plan for a slick early commute, and check morning temperatures before irrigating or driving. A few quick steps tonight can prevent burst pipes, damaged gardens, and dangerous roads tomorrow.