Southside climate

Southside Frost Dates and Growing Season

NOAA 1991-2020 normals for Gadsden, 11.2 km from Southside, elevation 565 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Gadsden. 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 19 and the first fall freeze around November 13, a growing season of about 240 days.

Median at 36°F
last April 1, first November 3
Median at 32°F
last March 19, first November 13
Median at 28°F
last March 4, first November 27

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 21Apr 14Apr 9Apr 5Apr 1Mar 30Mar 26Mar 21Mar 16
32°FApr 7Mar 31Mar 27Mar 23Mar 19Mar 15Mar 11Mar 6Feb 27
28°FMar 24Mar 18Mar 13Mar 9Mar 4Mar 1Feb 25Feb 19Feb 11
24°FMar 15Mar 6Feb 28Feb 23Feb 17Feb 10Feb 4Jan 31Jan 21
20°FMar 2Feb 20Feb 11Feb 4Jan 31Jan 27Jan 21Jan 13Jan 4
16°FFeb 14Feb 4Jan 31Jan 29Jan 23Jan 18Jan 13Jan 8Dec 31

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 22Oct 26Oct 30Nov 1Nov 3Nov 5Nov 8Nov 12Nov 18
32°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 20Nov 25Dec 1
28°FNov 9Nov 14Nov 18Nov 23Nov 27Dec 1Dec 5Dec 9Dec 23
24°FNov 18Nov 27Dec 2Dec 7Dec 13Dec 22Dec 28Jan 3Jan 11
20°FDec 4Dec 12Dec 22Dec 28Jan 1Jan 6Jan 11Jan 16Jan 28
16°FDec 19Dec 28Jan 1Jan 6Jan 11Jan 15Jan 20Jan 26Feb 1

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°F237230224219215210206200193
32°F268258252246240235230224217
28°F299288280273268261255249241
24°F332321311305299292285276264
20°F365351343335330323314306296
16°F365365365363355346337331320

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
99% of years
20°F or colder
89% of years
16°F or colder
60% 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
2,781
Cooling degree days, base 65°F
2,018
Growing degree days, base 40°F
8,524
Growing degree days, base 45°F
6,913
Growing degree days, base 50°F
5,448
Growing degree days, base 55°F
4,140
Growing degree days, base 60°F
2,995

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January688040
February512159
March33414199
April12656385
May24201642
June1386835
July0498962
August0476941
September6300744
October11280437
November3776146
December601159

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 11.2 km from Southside. 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 USC00013154 (Gadsden). Public domain.