Opp climate

Opp Frost Dates and Growing Season

NOAA 1991-2020 normals for Andalusia Opp AP, 13.5 km from Opp, elevation 310 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Andalusia Opp AP. 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 February 28 and the first fall freeze around November 28, a growing season of about 274 days.

Median at 36°F
last March 14, first November 16
Median at 32°F
last February 28, first November 28
Median at 28°F
last February 11, first December 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 1Mar 26Mar 21Mar 17Mar 14Mar 10Mar 4Feb 28Feb 21
32°FMar 20Mar 14Mar 9Mar 4Feb 28Feb 24Feb 19Feb 12Feb 1
28°FMar 10Mar 1Feb 24Feb 18Feb 11Feb 5Jan 31Jan 23Jan 11
24°FFeb 28Feb 18Feb 9Feb 2Jan 29Jan 22Jan 15Jan 3Dec 26
20°FFeb 9Feb 3Jan 29Jan 25Jan 18Jan 13Jan 5Dec 31Dec 22
16°F–––––––––

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°FNov 1Nov 5Nov 8Nov 12Nov 16Nov 19Nov 23Nov 30Dec 6
32°FNov 8Nov 14Nov 19Nov 24Nov 28Dec 2Dec 7Dec 16Jan 1
28°FNov 20Nov 28Dec 3Dec 8Dec 18Dec 28Jan 3Jan 11Jan 21
24°FDec 2Dec 11Dec 23Dec 31Jan 4Jan 10Jan 17Jan 28Feb 7
20°FDec 13Dec 26Dec 31Jan 4Jan 11Jan 17Jan 23Jan 30Feb 5
16°F–––––––––

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°F275264258252247242236230220
32°F310298289282274268261254245
28°F348334327318309302292284272
24°F365365364352344335329320306
20°F365365365365365365360346332
16°F365365365365365365365365365

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
95% of years
24°F or colder
73% of years
20°F or colder
32% of years
16°F or colder
7% 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
1,494
Cooling degree days, base 65°F
2,912
Growing degree days, base 40°F
10,570
Growing degree days, base 45°F
8,807
Growing degree days, base 50°F
7,125
Growing degree days, base 55°F
5,566
Growing degree days, base 60°F
4,152

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January41214164
February28019206
March15768384
April36135550
May3330792
June0508958
July05861,051
August05701,035
September1435885
October43187609
November19741306
December36617185

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 13.5 km from Opp. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00053843 (Andalusia Opp AP). Public domain.