Will Pipes Freeze in Anchorage Municipality, AK? 104 nights a Year
Freeze nights in Anchorage Municipality
In a normal year Anchorage Municipality, AK gets 104 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 93% of US counties.
Risk level: Severe. The risk season runs October to April, worst in December.
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 | 104 nights |
| Insulated pipe in unheated space | 10°F | 55 nights |
| Inside the heated house | 0°F | 23 nights |
Foam-sleeving a bare pipe in unheated space takes it from 104 nights of risk to 55 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 09/23, last around 05/18. For 20°F: 10/20 to 04/11.
How cold Anchorage Municipality nights get
Average winter (Dec-Feb) low: 14°F; the coldest month, January, averages 12°F overnight. 9 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, April, October, November, December: 55 nights a year, and 23 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 12°F | 15°F | 16°F | 27°F | 36°F | 44°F | 48°F | 46°F | 39°F | 28°F | 17°F | 15°F |
Anchorage Municipality next to its neighbours
Matanuska-Susitna Borough, AK, 122 km north, gets 133 nights below 20°F to Anchorage Municipality's 104 nights. Chugach Census Area, AK, 184 km southeast, gets 32 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Anchorage Municipality, AK | - | 203 nights | 104 nights | 12°F |
| Matanuska-Susitna Borough, AK | 122 km north | 221 nights | 133 nights | 5°F |
| Chugach Census Area, AK | 184 km southeast | 129 nights | 32 nights | 25°F |
| Kenai Peninsula Borough, AK | 188 km southwest | 194 nights | 102 nights | 10°F |
| Denali Borough, AK | 281 km north | 242 nights | 172 nights | -6°F |
| Copper River Census Area, AK | 299 km east | 251 nights | 180 nights | -11°F |
| Fairbanks North Star Borough, AK | 413 km north | 226 nights | 169 nights | -11°F |
Anchorage Municipality within AK
Anchorage Municipality ranks 10 of 26 AK counties for nights below 20°F. The most is Southeast Fairbanks Census Area, AK at 192 nights, with a -19°F average winter low. The fewest is Ketchikan Gateway Borough, AK: 10 nights, winter lows near 32°F. At 3,993 ft, Anchorage Municipality sits 3,172 ft above the state's median county elevation of 822 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 Glen Alps, AK, 24 km away (distant 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.