Will Pipes Freeze in Jefferson County, NY? 77 nights a Year
Freeze nights in Jefferson County
In a normal year Jefferson County, NY gets 77 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 81% of US counties.
Risk level: Severe. The risk season runs October to April, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 151 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 77 nights |
| Insulated pipe in unheated space | 10°F | 42 nights |
| Inside the heated house | 0°F | 22 nights |
Foam-sleeving a bare pipe in unheated space takes it from 77 nights of risk to 42 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 05/11. For 20°F: 11/04 to 04/08.
How cold Jefferson County nights get
Average winter (Dec-Feb) low: 13°F; the coldest month, January, averages 10°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, November, December: 42 nights a year, and 22 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 10°F | 11°F | 21°F | 33°F | 44°F | 53°F | 59°F | 57°F | 49°F | 39°F | 30°F | 19°F |
Jefferson County next to its neighbours
Lewis County, NY, 54 km southeast, gets 86 nights below 20°F to Jefferson County's 77 nights. Oswego County, NY, 61 km south, gets 63 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Jefferson County, NY | - | 151 nights | 77 nights | 10°F |
| Lewis County, NY | 54 km southeast | 165 nights | 86 nights | 8°F |
| Oswego County, NY | 61 km south | 147 nights | 63 nights | 13°F |
| St. Lawrence County, NY | 95 km northeast | 162 nights | 86 nights | 6°F |
| Oneida County, NY | 97 km southeast | 147 nights | 67 nights | 13°F |
| Herkimer County, NY | 108 km southeast | 186 nights | 102 nights | 6°F |
| Onondaga County, NY | 111 km south | 140 nights | 61 nights | 15°F |
Jefferson County within NY
Jefferson County ranks 16 of 62 NY counties for nights below 20°F. The most is Franklin County, NY at 107 nights, with a 7°F average winter low. The fewest is Bronx County, NY: 16 nights, winter lows near 30°F. At 289 ft, Jefferson County sits 598 ft below the state's median county elevation of 888 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 Watertown International Airport, NY, 3 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.