Windom climate

Windom Frost Dates and Growing Season

NOAA 1991-2020 normals for Windom, 1.2 km from Windom, elevation 1384 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Windom. 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 30 and the first fall freeze around October 10, a growing season of about 162 days.

Median at 36°F
last May 8, first October 1
Median at 32°F
last April 30, first October 10
Median at 28°F
last April 19, first October 21

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 23May 17May 13May 11May 8May 5May 3Apr 30Apr 25
32°FMay 13May 8May 4May 2Apr 30Apr 27Apr 24Apr 21Apr 15
28°FMay 3Apr 30Apr 26Apr 23Apr 19Apr 16Apr 12Apr 8Apr 4
24°FApr 25Apr 21Apr 16Apr 13Apr 10Apr 7Apr 4Apr 1Mar 26
20°FApr 19Apr 12Apr 8Apr 5Apr 3Mar 31Mar 26Mar 22Mar 15
16°FApr 11Apr 5Apr 2Mar 30Mar 25Mar 21Mar 17Mar 13Mar 8

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 16Sep 21Sep 25Sep 27Oct 1Oct 3Oct 6Oct 9Oct 14
32°FSep 25Sep 29Oct 3Oct 6Oct 10Oct 13Oct 16Oct 20Oct 24
28°FOct 2Oct 10Oct 14Oct 17Oct 21Oct 23Oct 25Oct 29Nov 2
24°FOct 16Oct 22Oct 25Oct 27Oct 29Nov 1Nov 3Nov 7Nov 12
20°FOct 24Oct 30Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 21
16°FNov 1Nov 5Nov 8Nov 12Nov 15Nov 17Nov 20Nov 24Nov 29

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°F161156151147143139135130123
32°F182175171167162159155149142
28°F203195191186182178174168160
24°F221214209205201197192188180
20°F238231226222217213209205196
16°F256248243238234229224218211

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
7,402
Cooling degree days, base 65°F
813
Growing degree days, base 40°F
4,952
Growing degree days, base 45°F
3,896
Growing degree days, base 50°F
2,952
Growing degree days, base 55°F
2,123
Growing degree days, base 60°F
1,406

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,49900
February1,23201
March982012
April550487
May22349314
June35183599
July7281739
August15203652
September12984412
October4849121
November917014
December1,33000

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 1.2 km from Windom. 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 USC00219033 (Windom). Public domain.