Haskell County climate

Haskell County Frost Dates and Growing Season

NOAA 1991-2020 normals for Sublette 7WSW, 16.5 km from Haskell County, elevation 2949 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sublette 7WSW. 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 23 and the first fall freeze around October 21, a growing season of about 179 days.

Median at 36°F
last May 1, first October 11
Median at 32°F
last April 23, first October 21
Median at 28°F
last April 12, first October 29

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 14May 10May 6May 4May 1Apr 29Apr 27Apr 24Apr 18
32°FMay 5May 2Apr 29Apr 26Apr 23Apr 20Apr 16Apr 13Apr 7
28°FApr 28Apr 23Apr 19Apr 16Apr 12Apr 8Apr 4Apr 1Mar 27
24°FApr 19Apr 12Apr 7Apr 4Apr 1Mar 30Mar 24Mar 18Mar 11
20°FApr 7Apr 2Mar 28Mar 22Mar 18Mar 14Mar 9Mar 6Mar 1
16°FMar 28Mar 20Mar 14Mar 9Mar 6Mar 3Feb 28Feb 24Feb 17

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 27Oct 2Oct 5Oct 8Oct 11Oct 13Oct 16Oct 20Oct 23
32°FOct 5Oct 11Oct 15Oct 18Oct 21Oct 23Oct 26Oct 29Nov 2
28°FOct 15Oct 20Oct 22Oct 26Oct 29Oct 31Nov 2Nov 5Nov 9
24°FOct 22Oct 27Oct 31Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19
20°FOct 29Nov 3Nov 8Nov 11Nov 15Nov 18Nov 21Nov 25Dec 1
16°FNov 5Nov 12Nov 17Nov 21Nov 25Nov 28Dec 1Dec 6Dec 14

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°F179173168164160157153148141
32°F201194188184179175171166160
28°F221213208202199195190184177
24°F243234228222217213208202194
20°F264257251246240234229223215
16°F290280273267261257251244235

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
4,463
Cooling degree days, base 65°F
1,530
Growing degree days, base 40°F
6,881
Growing degree days, base 45°F
5,511
Growing degree days, base 50°F
4,296
Growing degree days, base 55°F
3,232
Growing degree days, base 60°F
2,311

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January94503
February746017
March551494
April30418216
May104110476
June9314756
July1452916
August2391854
September39204616
October25136287
November601157
December91005

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 16.5 km from Haskell 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 USC00147922 (Sublette 7WSW). Public domain.