Will my pipes freeze tonight?
See the next seven nights of forecast lows for your town, pick where your pipes run, and get a short checklist of what to do first. Uses National Weather Service forecasts.
General guidance based on published sources and the National Weather Service forecast. It can’t tell you for certain whether your pipes will freeze; drafts, wind and how long the cold lasts all matter. If a pipe bursts, shut off the main water valve and call a plumber. NeighborFix Guide is a free referral service, not a plumbing contractor.
About this tool
Pick a night from the National Weather Service forecast and tell the checker where your pipes run. It rates the risk and gives you a short list of what to do first.
How it works
Where the lows come from
The checker asks the National Weather Service for the point forecast at your town’s location and shows the forecast low for each of the next seven nights. The forecast is saved in your browser for an hour so it isn’t fetched again on every visit. If the forecast can’t be loaded, it shows the town’s average monthly lows from NOAA’s 1991 to 2020 climate normals instead and says so. Average lows are much milder than the coldest nights, so you can also type in a low yourself.
Temperature bands
- Above 32°F: water can’t freeze, so the risk is low wherever the pipe is.
- 21 to 32°F: exposed pipes can freeze.
- 20°F or below: the Insurance Institute for Business & Home Safety (IBHS) says unprotected pipes begin to freeze at 20°F. The figure traces back to University of Illinois Building Research Council tests, where uninsulated pipes in an unheated attic started freezing at 20°F or colder.
Where the pipe runs
Pipes inside heated rooms are treated as protected, pipes in outside walls as partly exposed, and pipes in a crawlspace, attic or unheated garage as exposed. The Red Cross lists all of those among the places pipes freeze most often. If the heat is off or nobody is home, every pipe counts as exposed.
| Pipe location | 21 to 32°F | 20°F or below |
|---|---|---|
| Inside heated walls | Low | Low |
| Outside wall, bare | Some | High |
| Outside wall, some or full sleeves | Low | High (some), Some (full) |
| Crawlspace, attic or garage, bare | High | Severe |
| Crawlspace, attic or garage, sleeved | Some | Severe (some), High (full) |
| Heat off or house empty | High (bare), Some (sleeved) | Severe |
The colored bar under each night uses the same table for the pipes you picked. These levels are our reading of the published guidance, not a lab measurement. Wind, drafts and how long the cold lasts can make things worse.
The checklist
You get three to six steps, most important first. They come from the Red Cross (drip faucets, open cabinet doors, keep the thermostat steady and at 55°F or higher when away, keep the garage door closed, drain outdoor faucets, add pipe sleeves or UL-listed heat tape) and from city water utility guidance on finding the main shutoff. Tick them off as you go.
Sources
- National Weather Service: API Web Service (api.weather.gov), point forecast endpoints, retrieved October 5, 2026
- American Red Cross: Preventing & Thawing Frozen Pipes, retrieved October 5, 2026
- International Code Council: Build It to Code to Minimize Damage from Frozen Water Pipes (cites the IBHS 20°F figure), retrieved October 5, 2026
- Gordon, J.R. (1996). An Investigation into Freezing and Bursting Water Pipes in Residential Construction. Building Research Council, University of Illinois, Research Report 96-1, retrieved October 5, 2026
- City of Bellevue Utilities: Prevent frozen pipes, and what to do if one breaks, retrieved October 5, 2026
- NOAA NCEI U.S. Climate Normals 1991 to 2020, monthly normals for each town’s nearest station, retrieved October 5, 2026
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