Fulton County climate

Fulton County Frost Dates and Growing Season

NOAA 1991-2020 normals for Atlanta Fulton CO AP, 5.2 km from Fulton County, elevation 840 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Atlanta Fulton CO 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 March 24 and the first fall freeze around November 8, a growing season of about 231 days.

Median at 36°F
last April 7, first October 29
Median at 32°F
last March 24, first November 8
Median at 28°F
last March 9, first November 20

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 22Apr 16Apr 13Apr 10Apr 7Apr 4Mar 31Mar 28Mar 21
32°FApr 10Apr 4Mar 31Mar 28Mar 24Mar 20Mar 16Mar 12Mar 2
28°FMar 27Mar 21Mar 17Mar 13Mar 9Mar 3Feb 28Feb 24Feb 15
24°FMar 15Mar 6Feb 28Feb 24Feb 19Feb 14Feb 8Feb 1Jan 22
20°FMar 4Feb 21Feb 12Feb 7Feb 1Jan 29Jan 22Jan 15Jan 5
16°FFeb 17Feb 7Feb 2Jan 29Jan 25Jan 19Jan 13Jan 7Dec 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 17Oct 22Oct 24Oct 27Oct 29Nov 1Nov 3Nov 6Nov 11
32°FOct 27Oct 31Nov 1Nov 5Nov 8Nov 11Nov 14Nov 19Nov 26
28°FNov 4Nov 9Nov 13Nov 17Nov 20Nov 26Dec 1Dec 6Dec 14
24°FNov 15Nov 21Nov 28Dec 2Dec 7Dec 13Dec 22Dec 31Jan 7
20°FDec 1Dec 8Dec 18Dec 26Jan 1Jan 4Jan 10Jan 17Jan 29
16°FDec 14Dec 26Jan 1Jan 4Jan 9Jan 14Jan 19Jan 27Feb 3

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°F228221215210206202197192186
32°F258248242236231226222215207
28°F290280273265259253246241231
24°F333319311303295287281271261
20°F364352339334328322312303289
16°F365365365360351344337331320

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
91% of years
16°F or colder
65% 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
2,775
Cooling degree days, base 65°F
1,825
Growing degree days, base 40°F
8,309
Growing degree days, base 45°F
6,687
Growing degree days, base 50°F
5,219
Growing degree days, base 55°F
3,912
Growing degree days, base 60°F
2,781

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January664046
February491167
March3399186
April14142357
May29178614
June0356805
July0468933
August0442907
September8261703
October12762406
November3855134
December592162

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 5.2 km from Fulton County. 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 USW00003888 (Atlanta Fulton CO AP). Public domain.