Wataga climate

Wataga Frost Dates and Growing Season

NOAA 1991-2020 normals for Galesburg, 12.4 km from Wataga, elevation 761 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Galesburg. 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 20 and the first fall freeze around October 19, a growing season of about 180 days.

Median at 36°F
last April 30, first October 9
Median at 32°F
last April 20, first October 19
Median at 28°F
last April 10, 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 15May 10May 6May 4Apr 30Apr 28Apr 25Apr 21Apr 17
32°FMay 5Apr 30Apr 26Apr 22Apr 20Apr 17Apr 15Apr 11Apr 6
28°FApr 24Apr 19Apr 16Apr 12Apr 10Apr 7Apr 5Apr 2Mar 28
24°FApr 15Apr 10Apr 6Apr 4Apr 1Mar 30Mar 27Mar 22Mar 18
20°FApr 8Apr 3Mar 31Mar 27Mar 23Mar 20Mar 17Mar 12Mar 7
16°FMar 30Mar 25Mar 21Mar 18Mar 15Mar 11Mar 8Mar 4Feb 28

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 3Oct 6Oct 9Oct 11Oct 14Oct 17Oct 21
32°FOct 4Oct 10Oct 13Oct 16Oct 19Oct 22Oct 24Oct 27Oct 30
28°FOct 14Oct 19Oct 23Oct 25Oct 28Oct 30Nov 1Nov 4Nov 8
24°FOct 24Oct 28Oct 31Nov 2Nov 4Nov 7Nov 10Nov 15Nov 20
20°FNov 1Nov 4Nov 8Nov 11Nov 14Nov 18Nov 21Nov 26Dec 1
16°FNov 8Nov 13Nov 17Nov 21Nov 24Nov 28Dec 1Dec 5Dec 11

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°F180173168163159156152146141
32°F198192188183180176172167160
28°F217210206202199195191186180
24°F239231226222217214209205196
20°F260253247241237232226220212
16°F277269264259254249243237226

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
6,322
Cooling degree days, base 65°F
970
Growing degree days, base 40°F
5,497
Growing degree days, base 45°F
4,354
Growing degree days, base 50°F
3,330
Growing degree days, base 55°F
2,420
Growing degree days, base 60°F
1,629

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,33600
February1,09202
March837132
April4419130
May16870378
June19217648
July2303766
August6250708
September93107467
October39414171
November782027
December1,15302

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 12.4 km from Wataga. 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 USC00113320 (Galesburg). Public domain.