Opelika climate

Opelika Frost Dates and Growing Season

NOAA 1991-2020 normals for Opelika, 6.9 km from Opelika, elevation 640 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Opelika. 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 March 29 and the first fall freeze around November 5, a growing season of about 223 days.

Median at 36°F
last April 10, first October 27
Median at 32°F
last March 29, first November 5
Median at 28°F
last March 13, first November 18

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 25Apr 20Apr 16Apr 13Apr 10Apr 7Apr 3Mar 31Mar 24
32°FApr 15Apr 9Apr 4Apr 1Mar 29Mar 25Mar 19Mar 14Mar 6
28°FApr 1Mar 27Mar 22Mar 16Mar 13Mar 8Mar 3Feb 26Feb 19
24°FMar 16Mar 11Mar 6Mar 2Feb 27Feb 22Feb 16Feb 8Jan 31
20°FMar 7Feb 28Feb 21Feb 14Feb 7Feb 2Jan 28Jan 20Jan 7
16°FFeb 25Feb 14Feb 5Jan 31Jan 27Jan 22Jan 14Jan 6Dec 27

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 12Oct 17Oct 21Oct 24Oct 27Oct 30Nov 1Nov 4Nov 9
32°FOct 22Oct 27Oct 31Nov 2Nov 5Nov 8Nov 12Nov 17Nov 22
28°FNov 1Nov 5Nov 10Nov 14Nov 18Nov 22Nov 27Dec 1Dec 7
24°FNov 14Nov 20Nov 26Nov 30Dec 2Dec 6Dec 13Dec 24Jan 2
20°FNov 26Dec 3Dec 8Dec 16Dec 26Jan 1Jan 6Jan 14Jan 26
16°FDec 8Dec 19Dec 28Jan 1Jan 7Jan 13Jan 18Jan 26Feb 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°F222213208203199195192187180
32°F250242234228223218214208200
28°F284273264258251246241234225
24°F320306299290283276269262251
20°F354341334326319311303294281
16°F365365365354345337332323309

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
94% of years
16°F or colder
68% 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
2,721
Cooling degree days, base 65°F
1,755
Growing degree days, base 40°F
8,290
Growing degree days, base 45°F
6,663
Growing degree days, base 50°F
5,180
Growing degree days, base 55°F
3,861
Growing degree days, base 60°F
2,717

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January642153
February483273
March33410196
April15241347
May32169602
June1334783
July0443908
August0420885
September7263706
October13265405
November3677151
December572271

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 6.9 km from Opelika. 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 USC00016129 (Opelika). Public domain.