Edgerton climate

Edgerton Frost Dates and Growing Season

NOAA 1991-2020 normals for Lake Wilson, 20 km from Edgerton, elevation 1653 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lake Wilson. 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 May 7 and the first fall freeze around September 29, a growing season of about 145 days.

Median at 36°F
last May 15, first September 20
Median at 32°F
last May 7, first September 29
Median at 28°F
last April 28, first October 8

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 28May 24May 20May 17May 15May 13May 10May 7May 3
32°FMay 19May 14May 11May 9May 7May 4May 2Apr 29Apr 25
28°FMay 10May 6May 2Apr 30Apr 28Apr 25Apr 22Apr 18Apr 13
24°FMay 1Apr 27Apr 23Apr 20Apr 18Apr 15Apr 11Apr 7Apr 3
20°FApr 24Apr 19Apr 15Apr 11Apr 8Apr 5Apr 2Mar 30Mar 22
16°FApr 17Apr 10Apr 6Apr 3Apr 1Mar 29Mar 24Mar 19Mar 13

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 6Sep 11Sep 15Sep 18Sep 20Sep 23Sep 26Sep 30Oct 3
32°FSep 15Sep 20Sep 24Sep 27Sep 29Oct 2Oct 5Oct 8Oct 13
28°FSep 25Sep 30Oct 2Oct 5Oct 8Oct 12Oct 15Oct 19Oct 24
24°FOct 5Oct 10Oct 14Oct 18Oct 21Oct 24Oct 26Oct 29Nov 3
20°FOct 15Oct 21Oct 25Oct 27Oct 30Nov 1Nov 4Nov 7Nov 12
16°FOct 27Oct 31Nov 2Nov 4Nov 7Nov 9Nov 13Nov 16Nov 21

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°F146140135131127124120115108
32°F164157152149145142138134127
28°F185177172168164160156152146
24°F204199194190186181176171164
20°F227218212208204200195190184
16°F242235229224219215211207201

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
8,436
Cooling degree days, base 65°F
497
Growing degree days, base 40°F
4,201
Growing degree days, base 45°F
3,225
Growing degree days, base 50°F
2,361
Growing degree days, base 55°F
1,612
Growing degree days, base 60°F
984

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,62400
February1,34100
March1,11007
April669147
May31425228
June66110494
July19187634
August41126550
September19844315
October590479
November1,01707
December1,44800

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 20 km from Edgerton. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00214534 (Lake Wilson). Public domain.