Chouteau climate

Chouteau Frost Dates and Growing Season

NOAA 1991-2020 normals for Pryor, 13.8 km from Chouteau, elevation 625 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pryor. 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 5 and the first fall freeze around October 30, a growing season of about 207 days.

Median at 36°F
last April 17, first October 21
Median at 32°F
last April 5, first October 30
Median at 28°F
last March 23, first November 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 2Apr 28Apr 24Apr 21Apr 17Apr 14Apr 11Apr 6Apr 1
32°FApr 21Apr 15Apr 11Apr 8Apr 5Apr 2Mar 30Mar 26Mar 19
28°FApr 8Apr 4Mar 31Mar 27Mar 23Mar 19Mar 15Mar 11Mar 6
24°FMar 29Mar 21Mar 16Mar 12Mar 9Mar 6Mar 3Feb 28Feb 22
20°FMar 15Mar 10Mar 6Mar 3Feb 28Feb 24Feb 20Feb 15Feb 7
16°FMar 8Mar 3Feb 28Feb 22Feb 16Feb 11Feb 5Jan 31Jan 24

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°FOct 6Oct 12Oct 15Oct 18Oct 21Oct 23Oct 25Oct 29Nov 1
32°FOct 15Oct 21Oct 24Oct 27Oct 30Nov 1Nov 4Nov 8Nov 14
28°FOct 24Oct 30Nov 2Nov 5Nov 8Nov 12Nov 16Nov 21Nov 27
24°FNov 2Nov 7Nov 12Nov 17Nov 20Nov 26Dec 1Dec 3Dec 9
20°FNov 11Nov 20Nov 25Nov 30Dec 2Dec 5Dec 9Dec 14Dec 19
16°FNov 26Dec 1Dec 6Dec 11Dec 16Dec 20Dec 24Dec 29Jan 6

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°F203197192189185181177173166
32°F230222216211207203198193185
28°F255247241236231226220214206
24°F281273267261255249244238228
20°F302293287281276271265259250
16°F332321314307301295288281271

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
3,874
Cooling degree days, base 65°F
1,728
Growing degree days, base 40°F
7,472
Growing degree days, base 45°F
6,034
Growing degree days, base 50°F
4,741
Growing degree days, base 55°F
3,591
Growing degree days, base 60°F
2,587

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January897011
February681025
March4985112
April22932278
May52133546
June2335783
July0477942
August0465930
September27230653
October19843328
November4867113
December805022

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 13.8 km from Chouteau. 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 USC00347309 (Pryor). Public domain.