Will Pipes Freeze in Pima County, AZ? 2 nights a Year
Freeze nights in Pima County
In a normal year Pima County, AZ gets 2 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 11% of US counties.
Risk level: Occasional. The risk season runs December to January, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 36 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 2 nights |
| Insulated pipe in unheated space | 10°F | none |
| Inside the heated house | 0°F | none |
Foam-sleeving a bare pipe in unheated space takes it from 2 nights of risk to none. 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 11/09, last around 03/27. For 20°F: 12/18 to 01/22.
How cold Pima County nights get
Average winter (Dec-Feb) low: 36°F; the coldest month, December, averages 35°F overnight. 6 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, Nov, Dec).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 36°F | 38°F | 42°F | 47°F | 54°F | 64°F | 70°F | 69°F | 64°F | 53°F | 42°F | 35°F |
Pima County next to its neighbours
Cochise County, AZ, 192 km east, gets 7 nights below 20°F to Pima County's 2 nights. Pinal County, AZ, 96 km northeast, gets under 1 night.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Pima County, AZ | - | 36 nights | 2 nights | 36°F |
| Pinal County, AZ | 96 km northeast | 22 nights | under 1 night | 39°F |
| Santa Cruz County, AZ | 111 km southeast | 48 nights | 3 nights | 34°F |
| Maricopa County, AZ | 151 km northwest | 6 nights | none | 43°F |
| Cochise County, AZ | 192 km east | 73 nights | 7 nights | 30°F |
| Graham County, AZ | 200 km northeast | 75 nights | 9 nights | 29°F |
| Gila County, AZ | 206 km northeast | 24 nights | under 1 night | 36°F |
Pima County within AZ
Pima County ranks 10 of 15 AZ counties for nights below 20°F. The most is Coconino County, AZ at 67 nights, with a 20°F average winter low. The fewest is Maricopa County, AZ: none, winter lows near 43°F. At 3,473 ft, Pima County sits 598 ft below the state's median county elevation of 4,072 ft.
What to do here
- Keep a night-of routine: drip, open cabinets, keep the heat at 55F or above.
- Foam-sleeve any pipe in the garage or crawlspace once; it is cheap and lasts years.
Which pipe gets which threshold: the 32, 20, 10 and 0 rule.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Anvil Rch, AZ, 41 km away (distant match). A normal year, not tonight's forecast: check the forecast low for the night itself. What a "fair" or "distant" station match means is in the method guide.