Excel climate

Excel Frost Dates and Growing Season

NOAA 1991-2020 normals for Atmore, 28.9 km from Excel, elevation 300 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Atmore. 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 27, a growing season of about 270 days.

Median at 36°F
last March 16, first November 14
Median at 32°F
last February 28, first November 27
Median at 28°F
last February 12, first December 14

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 4Mar 30Mar 25Mar 20Mar 16Mar 12Mar 7Mar 1Feb 23
32°FMar 21Mar 15Mar 9Mar 4Feb 28Feb 25Feb 19Feb 12Feb 1
28°FMar 10Mar 1Feb 25Feb 18Feb 12Feb 5Jan 31Jan 23Jan 11
24°FFeb 28Feb 16Feb 7Feb 2Jan 28Jan 23Jan 16Jan 10Dec 31
20°FFeb 14Feb 4Jan 31Jan 27Jan 22Jan 17Jan 12Jan 5Dec 28
16°FFeb 7Feb 1Jan 24Jan 19Jan 16Jan 13Jan 9Jan 5Jan 1

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 31Nov 3Nov 7Nov 10Nov 14Nov 17Nov 21Nov 26Dec 1
32°FNov 8Nov 14Nov 19Nov 23Nov 27Dec 1Dec 4Dec 11Dec 24
28°FNov 18Nov 27Dec 2Dec 7Dec 14Dec 23Dec 31Jan 4Jan 15
24°FDec 3Dec 12Dec 22Dec 29Jan 2Jan 7Jan 13Jan 21Feb 1
20°FDec 15Dec 27Jan 1Jan 7Jan 12Jan 17Jan 22Jan 30Feb 4
16°FDec 28Jan 1Jan 5Jan 9Jan 13Jan 17Jan 21Jan 27Feb 2

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°F270259252247242237231225217
32°F305293283276270264258251243
28°F341330320311305297289280266
24°F365365353343335330322310299
20°F365365365365365358347337327
16°F365365365365365365365365349

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
98% of years
24°F or colder
82% of years
20°F or colder
47% of years
16°F or colder
16% 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
1,757
Cooling degree days, base 65°F
2,673
Growing degree days, base 40°F
10,088
Growing degree days, base 45°F
8,353
Growing degree days, base 50°F
6,718
Growing degree days, base 55°F
5,214
Growing degree days, base 60°F
3,859

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4777123
February32815167
March19048340
April61115506
May6311770
June0474924
July05491,014
August05361,001
September1400849
October55169581
November23236281
December40713162

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 28.9 km from Excel. 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 USC00010402 (Atmore). Public domain.