Will Pipes Freeze in Larimer County, CO? 84 nights a Year
Freeze nights in Larimer County
In a normal year Larimer County, CO gets 84 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 85% of US counties.
Risk level: Severe. The risk season runs October to May, worst in December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 190 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 84 nights |
| Insulated pipe in unheated space | 10°F | 30 nights |
| Inside the heated house | 0°F | 8 nights |
Foam-sleeving a bare pipe in unheated space takes it from 84 nights of risk to 30 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 09/16, last around 06/05. For 20°F: 10/18 to 04/29.
How cold Larimer County nights get
Average winter (Dec-Feb) low: 17°F; the coldest month, February, averages 16°F overnight. 10 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, 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: 30 nights a year, and 8 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 17°F | 16°F | 22°F | 27°F | 35°F | 44°F | 50°F | 49°F | 41°F | 31°F | 24°F | 17°F |
Larimer County next to its neighbours
Boulder County, CO, 63 km south, gets 86 nights below 20°F to Larimer County's 84 nights. Broomfield County, CO, 87 km southeast, gets 58 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Larimer County, CO | - | 190 nights | 84 nights | 17°F |
| Boulder County, CO | 63 km south | 200 nights | 86 nights | 16°F |
| Jackson County, CO | 71 km west | 257 nights | 145 nights | 3°F |
| Grand County, CO | 80 km southwest | 265 nights | 154 nights | 2°F |
| Broomfield County, CO | 87 km southeast | 150 nights | 58 nights | 19°F |
| Gilpin County, CO | 89 km south | 235 nights | 126 nights | 13°F |
| Weld County, CO | 94 km east | 180 nights | 93 nights | 11°F |
Larimer County within CO
Larimer County ranks 41 of 64 CO counties for nights below 20°F. The most is Summit County, CO at 177 nights, with a 5°F average winter low. The fewest is Mesa County, CO: 44 nights, winter lows near 21°F. At 7,692 ft, Larimer County sits 812 ft above the state's median county elevation of 6,880 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.
At this many nights, foam alone is not the answer: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Rustic (9 mi WSW), CO, 20 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. How a county figure is built from stations: how the numbers are made.