Sherman County climate

Sherman County Frost Dates and Growing Season

NOAA 1991-2020 normals for Goodland, 2.5 km from Sherman County, elevation 3651 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Goodland. 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 2 and the first fall freeze around October 11, a growing season of about 158 days.

Median at 36°F
last May 12, first October 1
Median at 32°F
last May 2, first October 11
Median at 28°F
last April 23, first October 19

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 25May 20May 16May 14May 12May 9May 7May 4Apr 30
32°FMay 16May 11May 8May 5May 2Apr 30Apr 28Apr 25Apr 19
28°FMay 6May 2Apr 29Apr 26Apr 23Apr 20Apr 16Apr 13Apr 9
24°FApr 27Apr 22Apr 18Apr 14Apr 11Apr 8Apr 5Apr 1Mar 26
20°FApr 15Apr 10Apr 5Apr 3Mar 31Mar 28Mar 24Mar 18Mar 11
16°FApr 5Apr 1Mar 29Mar 24Mar 19Mar 15Mar 11Mar 6Mar 2

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 18Sep 24Sep 27Sep 29Oct 1Oct 3Oct 6Oct 9Oct 12
32°FSep 28Oct 2Oct 5Oct 8Oct 11Oct 13Oct 15Oct 18Oct 21
28°FOct 6Oct 11Oct 15Oct 17Oct 19Oct 21Oct 24Oct 26Oct 30
24°FOct 14Oct 19Oct 22Oct 24Oct 27Oct 29Nov 1Nov 5Nov 9
20°FOct 21Oct 27Oct 31Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19
16°FOct 29Nov 3Nov 7Nov 10Nov 14Nov 17Nov 21Nov 24Nov 29

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°F157151147144140137134130124
32°F177170166162158155151146140
28°F196190185182178174170165158
24°F219211207202198195190185179
20°F240233227222218213209203196
16°F262254248243238233227221214

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
5,794
Cooling degree days, base 65°F
990
Growing degree days, base 40°F
5,522
Growing degree days, base 45°F
4,321
Growing degree days, base 50°F
3,275
Growing degree days, base 55°F
2,377
Growing degree days, base 60°F
1,617

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,08001
February91404
March732034
April4743104
May21344318
June30201621
July3346807
August8276733
September100111467
October41810157
November762026
December1,06002

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 2.5 km from Sherman 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 USW00023065 (Goodland). Public domain.