ZIP 31405 Zone 9a

Georgia · USDA zone 9a, average annual extreme minimum 20°F to 25°F.

Nearest qualified station: SAVANNAH INTL AP, GA US (USW00003822), 6.5 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is March 2. Median first 32°F is November 30. The 50% growing-season length is 270 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

ProbabilityDateHow to read it
90%February 4Earlier date. A last 32°F on or after this day is common.
50%March 2Median.
10%March 25Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

ProbabilityDateHow to read it
10%November 11Earlier date. A first 32°F on or before this day is uncommon.
50%November 30Median.
90%December 28Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this longDays
10%304
50%270
90%243

28°F threshold

10%50%90%
Last, on or afterMarch 13February 13January 15
First, on or beforeNovember 24December 22January 17
Season at least339 days304 days267 days

36°F threshold

10%50%90%
Last, on or afterApril 6March 19February 26
First, on or beforeNovember 1November 16December 4
Season at least270 days242 days218 days

Station SAVANNAH INTL AP, GA US (USW00003822). Completeness flag S, 29 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 14 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Georgia cities