Will Pipes Freeze in Costilla County, CO? 120 nights a Year
Freeze nights in Costilla County
In a normal year Costilla County, CO gets 120 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 98% 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 | 210 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 120 nights |
| Insulated pipe in unheated space | 10°F | 60 nights |
| Inside the heated house | 0°F | 23 nights |
Foam-sleeving a bare pipe in unheated space takes it from 120 nights of risk to 60 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 05/31. For 20°F: 10/20 to 04/18.
How cold Costilla County nights get
Average winter (Dec-Feb) low: 9°F; the coldest month, January, averages 6°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, October, November, December: 60 nights a year, and 23 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 6°F | 12°F | 23°F | 27°F | 35°F | 42°F | 48°F | 48°F | 40°F | 29°F | 18°F | 9°F |
Costilla County next to its neighbours
Alamosa County, CO, 45 km northwest, gets 146 nights below 20°F to Costilla County's 120 nights. Huerfano County, CO, 62 km northeast, gets 54 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Costilla County, CO | - | 210 nights | 120 nights | 6°F |
| Alamosa County, CO | 45 km northwest | 222 nights | 146 nights | 0°F |
| Huerfano County, CO | 62 km northeast | 142 nights | 54 nights | 21°F |
| Conejos County, CO | 67 km west | 218 nights | 141 nights | 1°F |
| Taos County, NM | 80 km south | 203 nights | 108 nights | 9°F |
| Custer County, CO | 92 km north | 206 nights | 115 nights | 9°F |
| Rio Grande County, CO | 93 km west | 237 nights | 151 nights | -1°F |
Costilla County within CO
Costilla County ranks 19 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 8,060 ft, Costilla County sits 1,180 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.
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 San Luis (1 mi S), CO, 9 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.