Ashkum climate

Ashkum Frost Dates and Growing Season

NOAA 1991-2020 normals for Watseka 2 Nw, 19.4 km from Ashkum, elevation 620 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Watseka 2 Nw. 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 24 and the first fall freeze around October 16, a growing season of about 174 days.

Median at 36°F
last May 4, first October 5
Median at 32°F
last April 24, first October 16
Median at 28°F
last April 12, first October 26

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 21May 16May 11May 7May 4May 2Apr 29Apr 25Apr 21
32°FMay 10May 4Apr 30Apr 27Apr 24Apr 21Apr 18Apr 15Apr 10
28°FApr 29Apr 23Apr 19Apr 15Apr 12Apr 9Apr 6Apr 3Mar 30
24°FApr 17Apr 11Apr 6Apr 3Apr 1Mar 30Mar 26Mar 22Mar 16
20°FApr 5Apr 1Mar 29Mar 25Mar 21Mar 17Mar 14Mar 10Mar 4
16°FMar 30Mar 24Mar 18Mar 14Mar 11Mar 8Mar 4Feb 28Feb 22

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 22Sep 27Sep 30Oct 3Oct 5Oct 8Oct 11Oct 14Oct 18
32°FOct 1Oct 7Oct 10Oct 13Oct 16Oct 19Oct 21Oct 25Oct 28
28°FOct 13Oct 18Oct 21Oct 24Oct 26Oct 29Oct 31Nov 2Nov 8
24°FOct 24Oct 29Nov 1Nov 3Nov 5Nov 8Nov 12Nov 16Nov 22
20°FNov 3Nov 7Nov 11Nov 14Nov 18Nov 22Nov 25Nov 29Dec 4
16°FNov 10Nov 16Nov 21Nov 25Nov 28Dec 1Dec 5Dec 10Dec 17

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°F172166162158154150145139133
32°F194187182178174170166160153
28°F216209204200196192188184176
24°F242233227222219214211206198
20°F266259252247242237232226219
16°F290280274268262257251245237

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
6,047
Cooling degree days, base 65°F
892
Growing degree days, base 40°F
5,468
Growing degree days, base 45°F
4,296
Growing degree days, base 50°F
3,256
Growing degree days, base 55°F
2,334
Growing degree days, base 60°F
1,542

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,26801
February1,03903
March806234
April4498121
May16971377
June24202629
July4275736
August9214670
September90103466
October37117184
November726034
December1,09403

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 19.4 km from Ashkum. 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 USC00119021 (Watseka 2 Nw). Public domain.