Will Pipes Freeze in St. Louis County, MN? 130 nights a Year
Freeze nights in St. Louis County
In a normal year St. Louis County, MN gets 130 nights at or below 20°F, the point where bare pipes in a garage, attic or outside wall start to freeze. That is more than 99% of US counties.
Risk level: Severe. The risk season runs October to May, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 203 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 130 nights |
| Insulated pipe in unheated space | 10°F | 86 nights |
| Inside the heated house | 0°F | 55 nights |
Foam-sleeving a bare pipe in unheated space takes it from 130 nights of risk to 86 nights. A 12 ft heat-tape kit runs $17 to $37; an average burst-pipe repair is about $500.
Month by month
Nights at or below 20°F in a normal year.
First 32°F night is usually around 10/01, last around 05/12. For 20°F: 11/03 to 04/13.
How cold St. Louis County nights get
Average winter (Dec-Feb) low: 0°F; the coldest month, January, averages -4°F overnight. 11 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, Aug, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, April, November, December: 86 nights a year, and 55 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| -4°F | -1°F | 12°F | 26°F | 39°F | 49°F | 53°F | 51°F | 44°F | 32°F | 19°F | 5°F |
St. Louis County next to its neighbours
Itasca County, MN, 83 km west, gets 117 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| St. Louis County, MN | - | 203 nights | 130 nights | -4°F |
| Itasca County, MN | 83 km west | 190 nights | 117 nights | -4°F |
| Lake County, MN | 83 km east | 201 nights | 124 nights | -3°F |
| Carlton County, MN | 109 km south | 187 nights | 108 nights | 1°F |
| Koochiching County, MN | 120 km northwest | 197 nights | 124 nights | -5°F |
| Aitkin County, MN | 128 km southwest | 183 nights | 111 nights | -1°F |
| Douglas County, WI | 133 km south | 189 nights | 111 nights | 2°F |
St. Louis County within MN
St. Louis County ranks 1 of 87 MN counties for nights below 20°F. The fewest is Winona County, MN: 81 nights, winter lows near 12°F. At 1,586 ft, St. Louis County sits 472 ft above the state's median county elevation of 1,114 ft.
What to do here
- Treat it as a building fix, not a night-of routine: insulate, heat tape, seal crawlspace vents.
- An automatic leak shutoff pays for itself if one burst is avoided.
- Know where the main shutoff is before the first hard freeze.
Interior pipes have a threshold too: the four freeze points.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Eveleth Wastewater Plant, MN, 14 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. Why elevation is part of the blend: how county numbers are made.