Wamego climate

Wamego Frost Dates and Growing Season

NOAA 1991-2020 normals for Wamego 4 W, 5.8 km from Wamego, elevation 1166 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wamego 4 W. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 18 and the first fall freeze around October 19, a growing season of about 183 days.

Median at 36°F
last April 28, first October 10
Median at 32°F
last April 18, first October 19
Median at 28°F
last April 8, first October 28

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 10May 6May 3Apr 30Apr 28Apr 25Apr 22Apr 18Apr 13
32°FMay 2Apr 28Apr 23Apr 20Apr 18Apr 15Apr 12Apr 9Apr 4
28°FApr 23Apr 18Apr 14Apr 10Apr 8Apr 5Apr 2Mar 30Mar 25
24°FApr 14Apr 9Apr 5Apr 2Mar 31Mar 28Mar 24Mar 19Mar 13
20°FApr 4Mar 31Mar 27Mar 23Mar 19Mar 15Mar 12Mar 7Mar 1
16°FMar 27Mar 20Mar 16Mar 12Mar 9Mar 5Mar 1Feb 26Feb 20

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 26Sep 30Oct 3Oct 6Oct 10Oct 13Oct 16Oct 19Oct 22
32°FOct 3Oct 9Oct 14Oct 17Oct 19Oct 22Oct 24Oct 27Nov 1
28°FOct 14Oct 19Oct 23Oct 26Oct 28Oct 31Nov 2Nov 5Nov 10
24°FOct 23Oct 29Nov 1Nov 3Nov 5Nov 9Nov 12Nov 17Nov 24
20°FOct 30Nov 3Nov 6Nov 11Nov 14Nov 19Nov 24Nov 28Dec 3
16°FNov 5Nov 12Nov 16Nov 21Nov 25Nov 29Dec 2Dec 6Dec 13

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F184176172167164161157152145
32°F202196191187183179174169163
28°F223216211207203199195190182
24°F245236232226222218213207199
20°F265256251245239235230223216
16°F283275270264258253248240232

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
5,203
Cooling degree days, base 65°F
1,402
Growing degree days, base 40°F
6,440
Growing degree days, base 45°F
5,174
Growing degree days, base 50°F
4,040
Growing degree days, base 55°F
3,031
Growing degree days, base 60°F
2,150

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13101
February893010
March671365
April34617194
May11298455
June8280721
July0434899
August2371834
September59168561
October30229247
November661149
December1,01704

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 5.8 km from Wamego. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00148563 (Wamego 4 W). Public domain.