Hardin climate

Hardin Frost Dates and Growing Season

NOAA 1991-2020 normals for Hardin, 0.3 km from Hardin, elevation 2880 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hardin. 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 13 and the first fall freeze around September 29, a growing season of about 135 days.

Median at 36°F
last May 25, first September 18
Median at 32°F
last May 13, first September 29
Median at 28°F
last May 1, first October 7

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 9Jun 3May 31May 28May 25May 22May 19May 16May 13
32°FMay 26May 22May 19May 16May 13May 10May 7May 4Apr 30
28°FMay 13May 9May 5May 3May 1Apr 29Apr 26Apr 22Apr 16
24°FMay 4Apr 30Apr 27Apr 24Apr 21Apr 17Apr 14Apr 9Apr 4
20°FApr 26Apr 20Apr 16Apr 12Apr 8Apr 4Apr 1Mar 28Mar 20
16°FApr 14Apr 7Apr 3Mar 31Mar 28Mar 24Mar 19Mar 15Mar 10

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 3Sep 9Sep 13Sep 16Sep 18Sep 21Sep 23Sep 28Oct 1
32°FSep 14Sep 19Sep 23Sep 25Sep 29Oct 1Oct 3Oct 5Oct 10
28°FSep 24Sep 30Oct 2Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20
24°FOct 2Oct 7Oct 12Oct 14Oct 17Oct 20Oct 23Oct 26Oct 29
20°FOct 9Oct 16Oct 20Oct 23Oct 26Oct 29Nov 1Nov 4Nov 9
16°FOct 18Oct 24Oct 28Oct 31Nov 2Nov 5Nov 9Nov 13Nov 20

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°F13312612211811411010510092
32°F154148143140135132128124118
28°F176169165161158154151146138
24°F200192187182178174170165159
20°F222214209203199194188183176
16°F243235229223219214209203195

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
6,895
Cooling degree days, base 65°F
633
Growing degree days, base 40°F
4,660
Growing degree days, base 45°F
3,548
Growing degree days, base 50°F
2,597
Growing degree days, base 55°F
1,801
Growing degree days, base 60°F
1,145

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28200
February1,04102
March839012
April542159
May28313226
June7686462
July10261716
August19220667
September15250358
October523290
November90306
December1,22600

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 0.3 km from Hardin. 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 USC00243915 (Hardin). Public domain.