Frost Advisory vs. Freeze Watch vs. Freeze Warning: What to Do at Home
A frost advisory is early notice, a freeze watch is your real deadline, and a freeze warning means you are nearly out of time. Frost mainly threatens plants, so use the advisory to plan outdoor water jobs. When a freeze watch is issued, disconnect hoses, drain outdoor faucets and sprinkler lines, and protect exposed pipes. HomeGuard Weather is a pre-launch iPhone app with no hardware, planned at $59.99/year or $9.99/month, that turns those alerts into a checklist for your house.
The cold-weather alert ladder for homeowners
The National Weather Service issues these alerts to protect people, crops, and plants. None of them is written for your plumbing, so here is what each one means for the house and what to do when you see it.
| Alert | What it means | What it means for your house | What to do |
|---|---|---|---|
| Frost Advisory | Frost is expected or occurring and threatens sensitive plants. Frost can form even when the air stays a few degrees above freezing. | Early notice. Pipes and outdoor faucets are usually not at risk yet. | Bring in or cover tender plants, then plan hose, outdoor faucet, and sprinkler jobs before the first freeze. |
| Freeze Watch | Significant, widespread freezing temperatures are possible, but timing, location, or occurrence is still uncertain. | Your real deadline for outdoor water. | Disconnect and drain hoses, shut off and drain outdoor faucets, schedule or finish sprinkler winterization, and cover hose bibs. |
| Freeze Warning | Temperatures are expected to fall below 32°F for a long enough period to be damaging. Since October 2024 this also covers what used to be a Hard Freeze Warning. | Trapped outdoor water can freeze tonight. | Finish only the outdoor-water tasks you can do safely, then protect pipes in garages, crawl spaces, and exterior-wall cabinets. |
| Cold Weather Advisory | Temperatures or wind chills are cold enough to be hazardous to people without precautions. It replaced the Wind Chill Advisory in October 2024. | Deep cold is reaching indoor pipes in unheated and drafty spaces. | Keep the thermostat steady day and night, open sink cabinets on exterior walls, and keep garage doors closed. |
| Extreme Cold Watch or Warning | Dangerously cold temperatures or wind chills are possible (watch) or expected (warning). These replaced Wind Chill Watches and Warnings. | The highest risk of frozen and burst pipes. | Drip a faucet served by exposed pipe, check on the furnace, know where the main water shutoff is, and limit time outside. |
Wind chill measures how cold it feels on skin. Pipes respond to the actual air temperature, but wind blowing through gaps in a crawl space or garage can still chill exposed pipe faster.
Frost advisory: what it means for your house
Frost forms on clear, calm nights when grass, roofs, and car windshields cool below freezing even though the air a few feet up stays in the mid 30s. That is why a frost advisory is mostly about plants. Exact criteria vary by local National Weather Service office.
For the house, treat it as a heads-up. Look at the seven-day forecast for the first night at or below 32°F, and use the mild days in between to do the outdoor water jobs from the first freeze home checklist. If you have a sprinkler system, this is the time to book a blowout before contractors fill up.
Freeze watch: your real deadline
A freeze watch is the better action deadline because it still leaves you daylight and dry footing. Do these before the watch becomes a warning:
- Hoses: disconnect, drain, and store every garden hose. See when to disconnect garden hoses before a freeze.
- Outdoor faucets: close the indoor shutoff for each outdoor faucet if you have one, then open the outside faucet to drain. Add an insulated cover.
- Sprinkler and irrigation lines: shut off and drain the system, or schedule professional winterization. Follow the installer's or manufacturer's directions.
- Exposed pipes: check garages, crawl spaces, and unheated basements for pipe that needs insulation.
Freeze warning: finish only what is safe
A freeze warning means the freeze is expected, so time is short. Finish the outdoor-water tasks you can do safely in daylight, then move inside: open sink cabinets on exterior walls, keep the garage closed, and keep the thermostat steady overnight. The frozen pipe guide covers the night-before routine and how to thaw a pipe safely.
The National Weather Service no longer issues a separate Hard Freeze Warning. Read the forecast low in the Freeze Warning: around 28°F or lower for several hours is a hard freeze. The hard freeze warning checklist explains the change and the second pass for exposed pipes.
Why frost and freeze alerts stop after the growing season
Many National Weather Service offices issue frost advisories, freeze watches, and freeze warnings only during the growing season, because they exist to protect crops and plants. Once a widespread freeze ends the growing season in your area, those alerts often stop for the rest of the winter.
That catches homeowners out. The first freeze of the year comes with an alert, but the colder nights after it often do not. If your outdoor water is still connected in late fall, do not wait for another freeze warning. Watch the forecast low, and treat Cold Weather Advisories and Extreme Cold alerts as your signal for indoor pipe protection.
Read the forecast low, not just the alert name
- 33°F to 36°F on a clear, calm night: frost is possible. Protect plants and plan outdoor water jobs.
- 29°F to 32°F: a light freeze. Hoses and outdoor faucets should already be drained.
- Around 28°F or lower for several hours: a hard freeze. Check exposed pipes, garages, and crawl spaces.
- Single digits or below zero: deep cold. Keep the heat steady, open exterior-wall cabinets, and drip a faucet on exposed pipe.
These are practical homeowner ranges, not official alert criteria. Wind, insulation, and how long the cold lasts matter as much as the number. For when your first freeze usually arrives, see when to winterize before the first freeze.
Print the free First Freeze Home Checklist PDF (or the ink-friendly version), or browse the full printable checklist library.
Why an app, not another weather alert
Weather alerts tell you about the weather, and some stop before winter really starts. HomeGuard watches the forecast low for your home and turns it into the short list of jobs that matter for your house: hoses before the first freeze, pipes before deep cold, vents before snow. It is software only, with no sensor, hub, valve, or device install, and it does not replace National Weather Service alerts.
Going away this winter? See what temperature to set your thermostat when away. Comparing software reminders with sensors or shutoff devices? Read the app vs. sensors and shutoff comparison.
Sources and further reading
This guide follows the National Weather Service cold-weather alert definitions, the NWS glossary entry for frost, the NWS cold-hazard product changes (effective October 1, 2024), and the American Red Cross frozen-pipe guidance. HomeGuard Weather is not affiliated with the National Weather Service.
FAQ
Is a frost advisory the same as a freeze warning?
No. A frost advisory means frost is expected and mainly threatens sensitive plants, often on clear, calm nights when the air stays a few degrees above freezing. A freeze warning means temperatures are expected to fall below 32°F for long enough to damage crops, plants, and exposed outdoor plumbing.
Should I disconnect my garden hose during a frost advisory?
It is a good time to do it. A hose left on the faucet during light frost is usually not at risk yet, but the next cold night may be a freeze. Disconnecting and draining hoses during the frost advisory means the first freeze watch is not a scramble.
What temperature is a freeze warning?
A freeze warning is issued when temperatures are expected to fall below 32°F for a long enough period to be damaging. Exact criteria vary by local National Weather Service office. Check the forecast low: around 28°F or lower for several hours is what used to be called a hard freeze.
What happened to the hard freeze warning?
Since October 1, 2024, the National Weather Service has issued hard freeze risk as a Freeze Warning instead of a separate Hard Freeze Warning, and Hard Freeze Watches became Freeze Watches. Read the forecast low in the Freeze Warning to tell how hard the freeze will be.
Why did freeze warnings stop in my area?
Many National Weather Service offices issue frost advisories and freeze warnings only during the growing season. Once a widespread freeze ends the growing season in your area, those alerts often stop for the winter, even though colder nights are coming. Watch the forecast low instead of waiting for an alert.
Is HomeGuard Weather available in the App Store?
Not yet. HomeGuard Weather is pre-launch and collecting early-access interest for the iPhone app. Planned pricing is $59.99/year or $9.99/month.