Bibb County climate

Bibb County Frost Dates and Growing Season

NOAA 1991-2020 normals for Macon Middle Ga Rgnl AP, 14.2 km from Bibb County, elevation 343 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Macon Middle Ga Rgnl 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 21 and the first fall freeze around November 10, a growing season of about 235 days.

Median at 36°F
last April 3, first November 1
Median at 32°F
last March 21, first November 10
Median at 28°F
last March 3, first November 24

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 19Apr 14Apr 10Apr 7Apr 3Apr 1Mar 28Mar 23Mar 17
32°FApr 7Apr 2Mar 29Mar 25Mar 21Mar 18Mar 13Mar 8Feb 28
28°FMar 24Mar 18Mar 13Mar 7Mar 3Feb 28Feb 22Feb 15Feb 5
24°FMar 12Mar 2Feb 25Feb 19Feb 14Feb 7Feb 1Jan 27Jan 18
20°FFeb 23Feb 11Feb 6Feb 1Jan 29Jan 24Jan 18Jan 9Dec 30
16°FFeb 8Feb 2Jan 30Jan 26Jan 22Jan 17Jan 12Jan 6Dec 26

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 20Oct 24Oct 27Oct 29Nov 1Nov 2Nov 5Nov 8Nov 13
32°FOct 29Nov 1Nov 4Nov 7Nov 10Nov 14Nov 17Nov 21Nov 29
28°FNov 6Nov 11Nov 16Nov 20Nov 24Nov 29Dec 3Dec 8Dec 21
24°FNov 18Nov 26Dec 2Dec 7Dec 15Dec 24Dec 31Jan 5Jan 14
20°FDec 3Dec 12Dec 24Dec 31Jan 4Jan 9Jan 15Jan 22Feb 2
16°FDec 23Jan 1Jan 6Jan 11Jan 16Jan 20Jan 25Jan 30Feb 6

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°F232224219215211206202196189
32°F260252246240235230225219212
28°F297287279273267260255247238
24°F340327317309301295287278267
20°F365365353344337332325316304
16°F365365365365365365354343331

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
98% of years
20°F or colder
79% of years
16°F or colder
38% 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
2,146
Cooling degree days, base 65°F
2,326
Growing degree days, base 40°F
9,363
Growing degree days, base 45°F
7,653
Growing degree days, base 50°F
6,077
Growing degree days, base 55°F
4,658
Growing degree days, base 60°F
3,403

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January542283
February3905116
March24924266
April9377436
May12257710
June0435885
July05421,007
August0510975
September3339786
October79112500
November29519209
December4834105

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 14.2 km from Bibb County. 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 USW00003813 (Macon Middle Ga Rgnl AP). Public domain.