Will Pipes Freeze in Johnson County, KS? 37 nights a Year
Freeze nights in Johnson County
In a normal year Johnson County, KS gets 37 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 53% of US counties.
Risk level: Regular. 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 | 101 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 37 nights |
| Insulated pipe in unheated space | 10°F | 12 nights |
| Inside the heated house | 0°F | 2 nights |
Foam-sleeving a bare pipe in unheated space takes it from 37 nights of risk to 12 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 10/29, last around 04/10. For 20°F: 11/26 to 03/10.
How cold Johnson County nights get
Average winter (Dec-Feb) low: 23°F; the coldest month, January, averages 20°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: 12 nights a year, and 2 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20°F | 24°F | 34°F | 44°F | 55°F | 65°F | 69°F | 67°F | 58°F | 47°F | 34°F | 25°F |
Johnson County next to its neighbours
Wyandotte County, KS, 26 km north, gets 45 nights below 20°F to Johnson County's 37 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Johnson County, KS | - | 101 nights | 37 nights | 20°F |
| Wyandotte County, KS | 26 km north | 113 nights | 45 nights | 19°F |
| Miami County, KS | 35 km south | 108 nights | 38 nights | 19°F |
| Leavenworth County, KS | 39 km northwest | 126 nights | 53 nights | 17°F |
| Douglas County, KS | 41 km west | 111 nights | 43 nights | 19°F |
| Jackson County, MO | 44 km east | 105 nights | 40 nights | 20°F |
| Cass County, MO | 48 km southeast | 107 nights | 41 nights | 20°F |
Johnson County within KS
Johnson County ranks 94 of 105 KS counties for nights below 20°F. The most is Rawlins County, KS at 83 nights, with a 16°F average winter low. The fewest is Cherokee County, KS: 27 nights, winter lows near 26°F. At 1,020 ft, Johnson County sits 505 ft below the state's median county elevation of 1,526 ft.
What to do here
- Insulate every pipe in unheated space before the season starts.
- Heat tape on the runs you cannot insulate well.
- Shut off and drain outdoor spigots for the season.
When to have the house ready: when freeze season starts.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Olathe (3 mi E), KS, 5 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.