Pratt County climate

Pratt County Frost Dates and Growing Season

NOAA 1991-2020 normals for Pratt 3NW, 4.2 km from Pratt County, elevation 1942 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pratt 3NW. 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 20, a growing season of about 183 days.

Median at 36°F
last April 30, first October 11
Median at 32°F
last April 20, first October 20
Median at 28°F
last April 9, 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 11May 7May 3May 1Apr 30Apr 27Apr 24Apr 21Apr 16
32°FMay 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 11Apr 6
28°FApr 23Apr 20Apr 16Apr 12Apr 9Apr 6Apr 4Mar 31Mar 26
24°FApr 17Apr 10Apr 6Apr 2Mar 31Mar 27Mar 22Mar 17Mar 11
20°FApr 3Mar 30Mar 25Mar 21Mar 17Mar 13Mar 9Mar 6Mar 1
16°FMar 27Mar 20Mar 15Mar 11Mar 7Mar 3Mar 1Feb 25Feb 20

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

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°F182176172168165161157152146
32°F202195190187183179175170164
28°F223215209205201197193187180
24°F246238232227222217213207200
20°F267258252246242237232225216
16°F287278272267261256251243233

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
4,989
Cooling degree days, base 65°F
1,442
Growing degree days, base 40°F
6,518
Growing degree days, base 45°F
5,223
Growing degree days, base 50°F
4,077
Growing degree days, base 55°F
3,069
Growing degree days, base 60°F
2,188

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,05101
February839010
March643162
April35412178
May11696450
June7295738
July1441905
August2389852
September51180580
October28727251
November650145
December98903

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 4.2 km from Pratt County. 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 USC00146549 (Pratt 3NW). Public domain.