Will Pipes Freeze in Johnson County, IN? 42 nights a Year
Freeze nights in Johnson County
In a normal year Johnson County, IN gets 42 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 58% of US counties.
Risk level: Severe. The risk season runs November to March, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 117 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 42 nights |
| Insulated pipe in unheated space | 10°F | 15 nights |
| Inside the heated house | 0°F | 4 nights |
Foam-sleeving a bare pipe in unheated space takes it from 42 nights of risk to 15 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 10/19, last around 04/20. For 20°F: 11/20 to 03/18.
How cold Johnson County nights get
Average winter (Dec-Feb) low: 21°F; the coldest month, January, averages 18°F overnight. 7 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, December: 15 nights a year, and 4 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 18°F | 20°F | 30°F | 40°F | 51°F | 61°F | 64°F | 61°F | 54°F | 41°F | 32°F | 24°F |
Johnson County next to its neighbours
Morgan County, IN, 30 km west, gets 44 nights below 20°F to Johnson County's 42 nights. Shelby County, IN, 26 km east, gets 39 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Johnson County, IN | - | 117 nights | 42 nights | 18°F |
| Shelby County, IN | 26 km east | 115 nights | 39 nights | 20°F |
| Morgan County, IN | 30 km west | 123 nights | 44 nights | 19°F |
| Marion County, IN | 32 km north | 114 nights | 42 nights | 20°F |
| Brown County, IN | 35 km south | 114 nights | 39 nights | 20°F |
| Bartholomew County, IN | 36 km southeast | 109 nights | 36 nights | 21°F |
| Hancock County, IN | 46 km northeast | 119 nights | 45 nights | 19°F |
Johnson County within IN
Johnson County ranks 54 of 92 IN counties for nights below 20°F. The most is Steuben County, IN at 63 nights, with a 19°F average winter low. The fewest is Floyd County, IN: 19 nights, winter lows near 29°F. At 759 ft, Johnson County sits close to the state's median county elevation of 759 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 Franklin Wastewater Plant, IN, 6 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.