Sheridan climate

Sheridan Frost Dates and Growing Season

NOAA 1991-2020 normals for Laurin 2NE, 12.6 km from Sheridan, elevation 5198 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Laurin 2NE. 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 24 and the first fall freeze around September 22, a growing season of about 117 days.

Median at 36°F
last June 12, first September 10
Median at 32°F
last May 24, first September 22
Median at 28°F
last May 10, first October 3

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°FJul 2Jun 26Jun 20Jun 16Jun 12Jun 9Jun 5Jun 2May 28
32°FJun 13Jun 5May 31May 28May 24May 21May 18May 15May 11
28°FMay 23May 18May 15May 12May 10May 7May 5May 2Apr 28
24°FMay 13May 8May 5May 2Apr 30Apr 27Apr 23Apr 19Apr 14
20°FMay 1Apr 26Apr 22Apr 19Apr 16Apr 12Apr 8Apr 5Mar 31
16°FApr 19Apr 11Apr 6Apr 3Mar 31Mar 27Mar 21Mar 14Mar 7

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 27Sep 1Sep 4Sep 7Sep 10Sep 13Sep 16Sep 20Sep 24
32°FSep 6Sep 11Sep 15Sep 20Sep 22Sep 25Sep 29Oct 2Oct 6
28°FSep 18Sep 24Sep 28Oct 1Oct 3Oct 6Oct 10Oct 14Oct 19
24°FSep 30Oct 4Oct 8Oct 12Oct 16Oct 19Oct 22Oct 26Oct 31
20°FOct 8Oct 14Oct 19Oct 23Oct 26Oct 29Nov 1Nov 5Nov 10
16°FOct 17Oct 23Oct 27Oct 31Nov 3Nov 7Nov 11Nov 14Nov 19

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°F11010296928783787263
32°F13813112612211711210710193
28°F166158153149146141137132124
24°F189182177172168163159154146
20°F213206201196191186181175168
16°F243233227221215210205198188

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
8,114
Cooling degree days, base 65°F
135
Growing degree days, base 40°F
3,199
Growing degree days, base 45°F
2,254
Growing degree days, base 50°F
1,489
Growing degree days, base 55°F
880
Growing degree days, base 60°F
426

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,24800
February1,08800
March94002
April723010
May477188
June2388235
July6065470
August7356449
September3016194
October665039
November99802
December1,30500

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 12.6 km from Sheridan. 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 USC00244896 (Laurin 2NE). Public domain.