Bushnell climate

Bushnell Frost Dates and Growing Season

NOAA 1991-2020 normals for Prairie City 2S, 5.5 km from Bushnell, elevation 650 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Prairie City 2S. 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 17 and the first fall freeze around October 22, a growing season of about 185 days.

Median at 36°F
last April 28, first October 12
Median at 32°F
last April 17, first October 22
Median at 28°F
last April 7, first October 30

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 12May 5May 2Apr 30Apr 28Apr 25Apr 22Apr 19Apr 15
32°FMay 2Apr 28Apr 23Apr 21Apr 17Apr 15Apr 12Apr 8Apr 4
28°FApr 21Apr 17Apr 13Apr 10Apr 7Apr 4Apr 2Mar 30Mar 22
24°FApr 14Apr 9Apr 5Apr 2Mar 31Mar 27Mar 22Mar 18Mar 13
20°FApr 5Apr 1Mar 28Mar 23Mar 20Mar 16Mar 13Mar 9Mar 4
16°FMar 29Mar 22Mar 18Mar 14Mar 12Mar 9Mar 6Mar 2Feb 25

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 29Oct 3Oct 6Oct 9Oct 12Oct 15Oct 18Oct 21Oct 24
32°FOct 7Oct 13Oct 17Oct 20Oct 22Oct 24Oct 26Oct 29Nov 1
28°FOct 18Oct 23Oct 25Oct 28Oct 30Nov 1Nov 4Nov 8Nov 13
24°FOct 28Nov 1Nov 3Nov 6Nov 8Nov 11Nov 14Nov 18Nov 24
20°FNov 5Nov 8Nov 12Nov 15Nov 17Nov 21Nov 24Nov 28Dec 4
16°FNov 11Nov 16Nov 20Nov 24Nov 27Dec 1Dec 4Dec 9Dec 16

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°F185178174170165162158154146
32°F203197193189185181177172166
28°F226217212208204201197192185
24°F245238233228223219215210204
20°F265258252247243239234229221
16°F285275269264260255250245237

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
5,886
Cooling degree days, base 65°F
1,017
Growing degree days, base 40°F
5,728
Growing degree days, base 45°F
4,541
Growing degree days, base 50°F
3,482
Growing degree days, base 55°F
2,538
Growing degree days, base 60°F
1,711

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,26001
February1,02305
March788240
April4089149
May14277406
June12222660
July2314776
August6254713
September74117495
October34722202
November735133
December1,08803

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 5.5 km from Bushnell. 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 USC00116970 (Prairie City 2S). Public domain.