Benkelman climate

Benkelman Frost Dates and Growing Season

NOAA 1991-2020 normals for Benkelman 1N, 1.9 km from Benkelman, elevation 3081 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Benkelman 1N. 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 30 and the first fall freeze around October 12, a growing season of about 163 days.

Median at 36°F
last May 9, first October 4
Median at 32°F
last April 30, first October 12
Median at 28°F
last April 19, first October 20

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 21May 16May 13May 11May 9May 6May 4May 2Apr 28
32°FMay 12May 7May 4May 2Apr 30Apr 28Apr 25Apr 21Apr 17
28°FMay 2Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 10Apr 5
24°FApr 23Apr 18Apr 14Apr 10Apr 8Apr 5Apr 1Mar 29Mar 22
20°FApr 14Apr 8Apr 4Apr 1Mar 29Mar 25Mar 21Mar 16Mar 10
16°FApr 4Mar 30Mar 25Mar 21Mar 16Mar 12Mar 8Mar 4Feb 28

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 21Sep 26Sep 29Oct 2Oct 4Oct 6Oct 8Oct 11Oct 14
32°FSep 29Oct 4Oct 7Oct 9Oct 12Oct 14Oct 16Oct 19Oct 22
28°FOct 8Oct 13Oct 16Oct 18Oct 20Oct 23Oct 25Oct 27Oct 30
24°FOct 15Oct 20Oct 23Oct 25Oct 28Oct 30Nov 1Nov 4Nov 9
20°FOct 22Oct 27Oct 31Nov 1Nov 4Nov 7Nov 11Nov 15Nov 21
16°FOct 30Nov 2Nov 7Nov 11Nov 14Nov 17Nov 21Nov 25Nov 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°F162157153149146143139134128
32°F179174170166163160156152145
28°F200194189185181177174169163
24°F221215210205201198193188180
20°F244236230225219215210204197
16°F265256251245241236229222215

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
5,738
Cooling degree days, base 65°F
1,156
Growing degree days, base 40°F
5,764
Growing degree days, base 45°F
4,559
Growing degree days, base 50°F
3,501
Growing degree days, base 55°F
2,580
Growing degree days, base 60°F
1,804

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,11000
February91804
March718038
April4445121
May18956349
June24237664
July2396859
August6323783
September88130497
October4019164
November759023
December1,07901

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 1.9 km from Benkelman. 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 USC00250760 (Benkelman 1N). Public domain.