Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 31405 — Savannah, GA

ZIP code 31405 (Savannah, Chatham County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 2 and the first fall frost November 30.

Where ZIP 31405 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostMar 2

First frostNov 30

2012 zone8b

Was 8b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Savannah, GA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Savannah, GA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 2median — 50% chance of a later frost

Safe for tender plantsMarch 25only 10% chance of frost after

First fall frostNovember 30median — 10% chance by Nov 11

Growing season270 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 13 and returns around December 22.

From the NOAA station Savannah Intl Airport, GA — 6 miles away, elevation 46 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 31405

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 19 – Feb 2

SpinachSow outdoors · Jan 19 – Feb 9

Broccoli, cabbageStart indoors · Dec 22 – Jan 5

Broccoli, cabbageTransplant · Feb 9 – Feb 23

Onion setsPlant outdoors · Feb 2 – Feb 16

PotatoesPlant outdoors · Feb 9 – Feb 23

LettuceSow outdoors · Feb 2 – Feb 16

Carrots, beetsSow outdoors · Feb 9 – Feb 23

TomatoesStart indoors · Jan 5 – Jan 19

TomatoesTransplant · Mar 9 – Mar 23

Peppers, eggplantStart indoors · Dec 22 – Jan 5

Peppers, eggplantTransplant · Mar 16 – Mar 30

BeansSow outdoors · Mar 9 – Mar 23

Sweet cornSow outdoors · Mar 9 – Mar 23

Cucumbers, squashSow outdoors · Mar 9 – Mar 23

Fall lettuce, spinachSow outdoors · Oct 5 – Oct 19

GarlicPlant cloves · Nov 16 – Dec 21

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 2) and first fall frost (Nov 30) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 31405 came on Jan 27 — about the same time as the 1991–2020 average (Jan 29).

average
Jan 292026
Jan 27

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 9a in Georgia

603 plants native to the lower 48 states, recorded in Georgia, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Savannah, GA.

Soil in Savannah, GA

The soil mapped at the center of ZIP 31405 is Cape Fear — loam, very poorly drained.

TextureLoama good balance for most vegetables

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter10%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Cape Fear soils.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 31405; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Savannah, GA

Summer high92 °Faverage high, July

Winter low40 °Faverage low, January

Hot days81days a year at 90 °F or more

Freezing nights21nights a year at 32 °F or less

Growing degree days6,657base 50 °F — the season’s usable heat

Longest day14 h 15 mindaylight on June 21

Shortest day10 h 03 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation52 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Savannah Intl Airport, GA (6 mi away); precipitation: Savannah 1.7 W, GA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

All 18 ZIP codes in Savannah → · Georgia planting zones →

Questions about 31405

What planting zone is ZIP code 31405?

ZIP code 31405 (Savannah, GA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Savannah, GA?

The median last spring frost (32 °F) near 31405 is March 2; after March 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Savannah Intl Airport station.

When is the first frost in Savannah, GA?

The median first fall frost near 31405 is November 30, giving a median frost-free growing season of 270 days.

When should I plant tomatoes in 31405?

Start tomato seeds indoors around Jan 5 – Jan 19 and set transplants outside around Mar 9 – Mar 23, one to three weeks after the median last frost.

How much rain and snow does 31405 get?

About 52 inches of precipitation a year (NOAA 1991–2020 normals, Savannah 1.7 W station).

How hot do summers get in Savannah, GA?

The average high peaks at 92 °F in July, with about 81 days a year at 90 °F or more.

What kind of soil does 31405 have?

The USDA soil survey maps Cape Fear at the center of ZIP 31405: loam, very poorly drained, pH about 5.5 (moderately acidic).

Did spring come early in Savannah, GA in 2026?

Spring leaf-out near 31405 came on Jan 27 in 2026, about the same as the 1991–2020 average (Jan 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Savannah, GA?

Short-day onions: the longest day near 31405 is 14 h 15 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 31405 change?

Yes. The 2012 USDA map put 31405 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.