Sheridan County climate

Sheridan County Frost Dates and Growing Season

NOAA 1991-2020 normals for Hay Springs, 30.5 km from Sheridan County, elevation 3855 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hay Springs. 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 14 and the first fall freeze around September 30, a growing season of about 138 days.

Median at 36°F
last May 24, first September 21
Median at 32°F
last May 14, first September 30
Median at 28°F
last May 3, first October 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°FJun 6Jun 1May 29May 27May 24May 21May 19May 16May 12
32°FMay 27May 23May 19May 16May 14May 11May 9May 5May 2
28°FMay 15May 11May 7May 5May 3May 1Apr 29Apr 25Apr 20
24°FMay 6May 1Apr 29Apr 26Apr 23Apr 21Apr 17Apr 14Apr 8
20°FApr 28Apr 24Apr 19Apr 16Apr 13Apr 9Apr 5Apr 1Mar 27
16°FApr 20Apr 14Apr 8Apr 5Apr 2Mar 30Mar 26Mar 21Mar 14

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 5Sep 10Sep 14Sep 18Sep 21Sep 23Sep 25Sep 28Oct 2
32°FSep 15Sep 21Sep 24Sep 27Sep 30Oct 2Oct 4Oct 7Oct 11
28°FSep 25Sep 30Oct 3Oct 5Oct 8Oct 11Oct 13Oct 16Oct 20
24°FOct 3Oct 9Oct 12Oct 15Oct 17Oct 20Oct 23Oct 25Oct 28
20°FOct 13Oct 18Oct 21Oct 23Oct 25Oct 27Oct 30Nov 2Nov 7
16°FOct 19Oct 24Oct 28Oct 30Nov 2Nov 5Nov 8Nov 11Nov 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°F13713112612311811411010597
32°F154148145141138134130124118
28°F174168164160156153150146139
24°F196188183179176172168163156
20°F216209203199194190185180174
16°F236228222218213208203197190

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
7,172
Cooling degree days, base 65°F
548
Growing degree days, base 40°F
4,371
Growing degree days, base 45°F
3,313
Growing degree days, base 50°F
2,414
Growing degree days, base 55°F
1,656
Growing degree days, base 60°F
1,031

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,25900
February1,05701
March884011
April632048
May34011194
June9684442
July16228677
August25177618
September18247332
October550282
November92209
December1,21000

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 30.5 km from Sheridan 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 USC00253710 (Hay Springs). Public domain.