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

Planting zone for 31328 — Tybee Island, GA

ZIP code 31328 (Tybee Island, 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 31328 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 Tybee Island, 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 Tybee Island, 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 — 20 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 31328

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 31328 came on Feb 2 — 5 days later than the 1991–2020 average (Jan 28).

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.

Trees 90

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °FAtlantic white cedar50 ft · blooms spring · medium shade tolerance · to −36 °F

Shrubs 146

Allegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Faloe yucca15 ft · blooms early summer · medium shade tolerance · to −1 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 176

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °FAmerican water horehound1.8 ft · blooms early summer · low shade tolerance · to −38 °F

Grasses 164

American cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °Fbig cordgrass8 ft · blooms spring · high shade tolerance · to −3 °F

Vines 13

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °F

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 Tybee Island, GA.

Soil in Tybee Island, GA

The soil mapped at the center of ZIP 31328 is Bohicket — silty clay, very poorly drained.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH7.3neutral; most vegetables like 6.0–7.0
DrainageVery poorly drainedconsider raised beds
Organic matter15%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Tidal marsh, salty (Bohicket).

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 31328; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tybee Island, 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
Precipitation51 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 61 °F, low 40 °F 61°40° JanFebruary: average high 65 °F, low 43 °F 65°43° FebMarch: average high 71 °F, low 49 °F 71°49° MarApril: average high 78 °F, low 55 °F 78°55° AprMay: average high 85 °F, low 63 °F 85°63° MayJune: average high 90 °F, low 71 °F 90°71° JunJuly: average high 92 °F, low 74 °F 92°74° JulAugust: average high 91 °F, low 73 °F 91°73° AugSeptember: average high 86 °F, low 69 °F 86°69° SepOctober: average high 79 °F, low 59 °F 79°59° OctNovember: average high 70 °F, low 48 °F 70°48° NovDecember: average high 64 °F, low 43 °F 64°43° Dec

Precipitation by month inches

0″2″4″6″January: 3.41 in precipitation 3.4 JanFebruary: 2.91 in precipitation 2.9 FebMarch: 3.60 in precipitation 3.6 MarApril: 3.58 in precipitation 3.6 AprMay: 3.70 in precipitation 3.7 MayJune: 5.89 in precipitation 5.9 JunJuly: 5.87 in precipitation 5.9 JulAugust: 6.58 in precipitation 6.6 AugSeptember: 4.89 in precipitation 4.9 SepOctober: 4.42 in precipitation 4.4 OctNovember: 2.67 in precipitation 2.7 NovDecember: 3.46 in precipitation 3.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Savannah Intl Airport, GA (20 mi away); precipitation: Daufuskie Island 1.7 Sw, SC (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

314109a
Savannah, GA · 6 mi
299159a
Daufuskie Island, SC · 8 mi
314169a
Savannah, GA · 9 mi
314119a
Savannah, GA · 10 mi
314049a
Savannah, GA · 10 mi
314039a
Savannah, GA · 11 mi
314149a
Savannah, GA · 11 mi
314189a
Savannah, GA · 11 mi

Georgia planting zones →

Questions about 31328

What planting zone is ZIP code 31328?

ZIP code 31328 (Tybee Island, 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 Tybee Island, GA?

The median last spring frost (32 °F) near 31328 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 Tybee Island, GA?

The median first fall frost near 31328 is November 30, giving a median frost-free growing season of 270 days.

When should I plant tomatoes in 31328?

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 31328 get?

About 51 inches of precipitation a year (NOAA 1991–2020 normals, Daufuskie Island 1.7 Sw station).

How hot do summers get in Tybee Island, 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 31328 have?

The USDA soil survey maps Bohicket at the center of ZIP 31328: silty clay, very poorly drained, pH about 7.3 (neutral).

Did spring come early in Tybee Island, GA in 2026?

Spring leaf-out near 31328 came on Feb 2 in 2026, 5 days later than the 1991–2020 average (Jan 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Tybee Island, GA?

Short-day onions: the longest day near 31328 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 31328 change?

Yes. The 2012 USDA map put 31328 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.