Freeze warning today: where it’s in effect, how cold it gets, and how to prepare overnight

An early-season cold snap is pushing sub-freezing air across the central U.S., triggering freeze warnings from the Upper Midwest into parts of the Great Lakes, Ohio Valley, central Appalachians, and portions of the central Plains. Many communities from Iowa and Illinois to Michigan, Nebraska, Kentucky, and West Virginia are looking at their first widespread freeze of the season between late tonight and early Friday. Lows are expected to dip into the upper 20s to low 30s for several hours before sunrise, enough to end the growing season in exposed spots and create slick patches on bridges where frost forms.

What a freeze warning means

A freeze warning is issued when forecasters expect temperatures at or below 32°F (0°C) long enough to damage or kill sensitive vegetation and unprotected outdoor plumbing. It often follows a frost advisory earlier in the season and, once verified, typically signals the end of the local growing season.

Related terms you may see:

• Frost Advisory: Temperatures generally 33–36°F (0.5–2°C) with light winds; frost forms on surfaces but not all locations drop to 32°F.

• Freeze Watch: Sub-freezing temperatures are possible—used 12–48 hours in advance.

• Hard Freeze Warning: Prolonged cold with lows ≤28°F (-2°C); higher risk to pipes and perennial plants.

Where freeze warnings are active today

Alerts are concentrated from the Midwest and Great Lakes into parts of the Ohio Valley and central Appalachians, with additional pockets in the central Plains. Communities in and around cities such as Des Moines, Quad Cities, Detroit’s western suburbs, Lincoln–Grand Island, eastern Kentucky valleys, and much of West Virginia are among those under frost or freeze headlines at various hours overnight. The coldest readings will favor low-lying areas and rural zones where winds lighten before dawn.

Timing window: The most likely period for sub-freezing temperatures is 2 a.m. to 9 a.m. local time Friday, though some spots will drop below freezing earlier, especially where skies clear quickly after sunset.

How cold will it get?

• Typical lows: 27–33°F for several hours pre-dawn.

• Locally colder pockets: 24–28°F in sheltered valleys and outlying rural areas.

• Urban cores/lakeshores: Often a few degrees milder, sometimes staying just above freezing; still expect frost on cars/roofs.

Even brief dips to 30–31°F can blacken tender plants; multiple hours in the 20s can impact late-season vegetables, annuals, and some perennials.

Quick checklist: protect pipes, pets, and plants

Pipes & homes

• Disconnect and drain garden hoses; shut off and cover outdoor spigots.

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

• Keep heat on overnight; set thermostats to at least 55°F (13°C) if you’re away.

• If using space heaters, place them on level surfaces, 3+ feet from anything flammable.

Pets & livestock

• Bring pets indoors; add dry bedding for outdoor animals and check heated waterers.

• Shield young or vulnerable animals from wind exposure in draft-free shelters.

Plants & gardens

• Cover tender plants with breathable fabric (frost cloth, sheets, burlap)—not plastic touching leaves.

• Water soil in the afternoon; moist soil holds heat better than dry.

• Move potted plants indoors or into garages; group containers together for shared warmth.

• After the event, wait until midday to assess damage; some plants perk up after light frost.

Vehicles & roads

• Expect windshield frost; place a towel or frost cover on glass tonight.

• Bridges and overpasses may turn patchy-slick before surrounding roads.

Travel and power impacts

This isn’t a winter storm, but a sharp radiational cool-down. The main issues are frost, icy spots on elevated surfaces, and heavier morning demand for heating, which can briefly spike energy usage. Widespread power outages are not expected from this event alone, though localized issues can occur if older lines or equipment are stressed by rapid temperature swings.

Why this cold snap is happening

A fresh, dry continental air mass has dropped south behind a midweek front. Cleared skies, light winds, and low humidity set the stage for radiational cooling, allowing heat to escape rapidly from the surface at night. That combination is classic for first freezes in late October.

What happens next

Daytime sunshine will bring a modest rebound Friday afternoon, but another chilly night is possible in some of the same regions if clouds and wind stay light. Farther south and east, frost and freeze headlines could expand into interior valleys if the dry air holds. Urban centers and immediate lakeshores will turn milder faster.

At-a-glance: alert types and thresholds

If you’re under a freeze warning tonight, a few minutes of preparation before bedtime—covering plants, securing pets, and winterizing outdoor faucets—will pay off by morning. Stay tuned to local forecasts for neighborhood-specific timing and any late-evening adjustments.