Pershing County climate

Pershing County Frost Dates and Growing Season

NOAA 1991-2020 normals for Rye Patch Dam, 8.9 km from Pershing County, elevation 4135 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rye Patch Dam. 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 May 19 and the first fall freeze around September 24, a growing season of about 125 days.

Median at 36°F
last June 4, first September 12
Median at 32°F
last May 19, first September 24
Median at 28°F
last May 4, first October 4

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°FJun 26Jun 18Jun 13Jun 8Jun 4Jun 2May 30May 23May 17
32°FJun 9Jun 3May 30May 24May 19May 16May 12May 7May 2
28°FMay 26May 18May 13May 8May 4May 1Apr 28Apr 24Apr 19
24°FMay 12May 3Apr 28Apr 24Apr 22Apr 19Apr 16Apr 10Apr 4
20°FApr 27Apr 20Apr 16Apr 11Apr 6Apr 2Mar 30Mar 23Mar 12
16°FApr 12Apr 4Mar 30Mar 23Mar 14Mar 8Mar 2Feb 25Feb 16

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°FAug 29Sep 2Sep 6Sep 9Sep 12Sep 15Sep 18Sep 21Sep 25
32°FSep 9Sep 14Sep 18Sep 21Sep 24Sep 26Sep 29Oct 2Oct 7
28°FSep 21Sep 26Sep 29Oct 2Oct 4Oct 7Oct 10Oct 14Oct 20
24°FOct 1Oct 4Oct 7Oct 11Oct 15Oct 18Oct 22Oct 26Nov 1
20°FOct 9Oct 15Oct 20Oct 24Oct 27Oct 30Nov 2Nov 7Nov 13
16°FOct 19Oct 25Oct 29Nov 1Nov 6Nov 9Nov 14Nov 20Nov 24

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°F1211121071029793888273
32°F148140135130125121116109102
28°F173165161156151147142135127
24°F200192186181176171166160151
20°F234223216210204197191185176
16°F270259251243236230222214202

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
5,748
Cooling degree days, base 65°F
691
Growing degree days, base 40°F
4,952
Growing degree days, base 45°F
3,749
Growing degree days, base 50°F
2,745
Growing degree days, base 55°F
1,919
Growing degree days, base 60°F
1,238

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,03400
February79501
March668014
April498063
May25819251
June71105486
July4300761
August10216671
September11350392
October4521101
November77606
December1,07100

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 8.9 km from Pershing County. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00267192 (Rye Patch Dam). Public domain.