Heavener climate

Heavener Frost Dates and Growing Season

NOAA 1991-2020 normals for Wister 3S, 11.1 km from Heavener, elevation 525 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wister 3S. 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 6 and the first fall freeze around November 2, a growing season of about 210 days.

Median at 36°F
last April 15, first October 24
Median at 32°F
last April 6, first November 2
Median at 28°F
last March 25, first November 12

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°FApr 30Apr 27Apr 23Apr 19Apr 15Apr 13Apr 9Apr 3Mar 28
32°FApr 24Apr 18Apr 13Apr 9Apr 6Apr 1Mar 29Mar 24Mar 18
28°FApr 15Apr 8Apr 3Mar 30Mar 25Mar 21Mar 16Mar 12Mar 4
24°FApr 4Mar 29Mar 23Mar 17Mar 13Mar 8Mar 4Feb 28Feb 20
20°FMar 22Mar 14Mar 9Mar 5Mar 1Feb 24Feb 18Feb 12Jan 31
16°FMar 9Mar 3Feb 26Feb 20Feb 14Feb 5Jan 31Jan 26Jan 16

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°FOct 9Oct 14Oct 18Oct 20Oct 24Oct 26Oct 29Nov 1Nov 6
32°FOct 18Oct 24Oct 27Oct 30Nov 2Nov 4Nov 7Nov 11Nov 17
28°FOct 30Nov 2Nov 5Nov 9Nov 12Nov 16Nov 19Nov 24Nov 30
24°FNov 5Nov 11Nov 16Nov 20Nov 24Nov 28Dec 2Dec 7Dec 12
20°FNov 14Nov 23Nov 28Dec 2Dec 7Dec 11Dec 17Dec 22Dec 29
16°FDec 1Dec 7Dec 13Dec 19Dec 25Dec 30Jan 3Jan 9Jan 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°F211204199195190186181176169
32°F235226219214210206202196189
28°F258248242236231226220213205
24°F286274267261256250244237228
20°F316305297290283277271264253
16°F346335326319311305299290280

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
98% 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
3,405
Cooling degree days, base 65°F
1,967
Growing degree days, base 40°F
8,040
Growing degree days, base 45°F
6,524
Growing degree days, base 50°F
5,156
Growing degree days, base 55°F
3,937
Growing degree days, base 60°F
2,876

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January807023
February598250
March44510141
April20239306
May48164582
June1384834
July0521986
August0496961
September15264699
October15077400
November41310138
December726137

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 11.1 km from Heavener. 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 USC00349724 (Wister 3S). Public domain.