Edgerton climate

Edgerton Frost Dates and Growing Season

NOAA 1991-2020 normals for Smithville Lake, 14.6 km from Edgerton, elevation 904 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Smithville Lake. 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 20, 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 20
Median at 28°F
last April 7, first October 29

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 13May 7May 3Apr 30Apr 28Apr 25Apr 22Apr 18Apr 14
32°FMay 3Apr 29Apr 25Apr 22Apr 18Apr 15Apr 12Apr 8Apr 4
28°FApr 23Apr 18Apr 13Apr 10Apr 7Apr 4Apr 2Mar 30Mar 23
24°FApr 14Apr 8Apr 4Apr 1Mar 29Mar 25Mar 21Mar 16Mar 9
20°FApr 3Mar 28Mar 23Mar 19Mar 16Mar 12Mar 8Mar 4Feb 28
16°FMar 24Mar 18Mar 13Mar 9Mar 6Mar 3Feb 28Feb 24Feb 17

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 25Sep 30Oct 4Oct 7Oct 10Oct 13Oct 16Oct 19Oct 23
32°FOct 5Oct 12Oct 15Oct 18Oct 20Oct 22Oct 25Oct 29Nov 1
28°FOct 15Oct 20Oct 24Oct 26Oct 29Oct 31Nov 2Nov 6Nov 11
24°FOct 22Oct 28Nov 1Nov 3Nov 5Nov 8Nov 12Nov 16Nov 23
20°FNov 1Nov 4Nov 8Nov 13Nov 16Nov 20Nov 24Nov 29Dec 4
16°FNov 7Nov 14Nov 18Nov 23Nov 27Dec 1Dec 3Dec 8Dec 15

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°F183177172167164160156151143
32°F202196192187183180175170163
28°F225217212208204200195190182
24°F248239232228223218214209200
20°F269260254249244239234228221
16°F288281275269264258253247238

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
5,532
Cooling degree days, base 65°F
1,194
Growing degree days, base 40°F
6,028
Growing degree days, base 45°F
4,800
Growing degree days, base 50°F
3,705
Growing degree days, base 55°F
2,739
Growing degree days, base 60°F
1,900

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,20001
February94706
March717351
April38911160
May14378408
June13244681
July1375838
August4329790
September74134512
October33620213
November682142
December1,02803

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 14.6 km from Edgerton. 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 USC00237862 (Smithville Lake). Public domain.