Hettinger climate

Hettinger Frost Dates and Growing Season

NOAA 1991-2020 normals for Hettinger Exp Stn, 0.9 km from Hettinger, elevation 2703 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hettinger Exp Stn. 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 21 and the first fall freeze around September 21, a growing season of about 120 days.

Median at 36°F
last June 2, first September 9
Median at 32°F
last May 21, first September 21
Median at 28°F
last May 11, first September 29

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 22Jun 14Jun 9Jun 5Jun 2May 30May 27May 24May 20
32°FJun 5May 31May 27May 24May 21May 18May 16May 14May 10
28°FMay 25May 19May 16May 13May 11May 9May 6May 4May 1
24°FMay 14May 9May 6May 4May 2Apr 30Apr 26Apr 22Apr 16
20°FMay 6May 1Apr 28Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7
16°FApr 28Apr 22Apr 19Apr 15Apr 12Apr 10Apr 7Apr 3Mar 29

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 23Aug 30Sep 2Sep 5Sep 9Sep 12Sep 14Sep 18Sep 23
32°FSep 5Sep 11Sep 15Sep 18Sep 21Sep 23Sep 26Sep 29Oct 2
28°FSep 16Sep 21Sep 24Sep 27Sep 29Oct 1Oct 4Oct 6Oct 10
24°FSep 23Sep 28Oct 1Oct 4Oct 6Oct 9Oct 12Oct 15Oct 19
20°FOct 1Oct 6Oct 10Oct 13Oct 16Oct 18Oct 21Oct 23Oct 27
16°FOct 11Oct 15Oct 19Oct 21Oct 24Oct 27Oct 30Nov 2Nov 7

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°F1171101061019792878070
32°F13713212712412011611210697
28°F156151146143140136131126120
24°F177170166162158154150145139
20°F195188184180176172168163157
16°F215208202198193189185180172

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
8,457
Cooling degree days, base 65°F
419
Growing degree days, base 40°F
3,870
Growing degree days, base 45°F
2,914
Growing degree days, base 50°F
2,089
Growing degree days, base 55°F
1,395
Growing degree days, base 60°F
834

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,50000
February1,27300
March1,07706
April707029
May3908156
June12259391
July28173610
August50142557
September22735282
October665256
November1,04102
December1,37800

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 0.9 km from Hettinger. 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 USC00324180 (Hettinger Exp Stn). Public domain.