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

Planting zone for Charleston, SC

Charleston, SC is in USDA zone 9a across its 13 ZIP codes. The median last spring frost is February 4 and the first fall frost December 30.

Charleston on the zone map

Outlined: its 7 ZIP code areas · 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
ZIP codes13
Last frostFeb 4
First frostDec 30
Growing season321 days

9a 13 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Charleston, SC

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 4median — 50% chance of a later frost
Safe for tender plantsMarch 4only 10% chance of frost after
First fall frostDecember 30median — 10% chance by Dec 2
Growing season321 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 24 and returns around January 8.

From the NOAA station Charleston City, SC, elevation 10 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 Charleston

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 24 – Jan 7
SpinachSow outdoors · Dec 24 – Jan 14
Broccoli, cabbageStart indoors · Nov 26 – Dec 10
Broccoli, cabbageTransplant · Jan 14 – Jan 28
Onion setsPlant outdoors · Jan 7 – Jan 21
PotatoesPlant outdoors · Jan 14 – Jan 28
LettuceSow outdoors · Jan 7 – Jan 21
Carrots, beetsSow outdoors · Jan 14 – Jan 28
TomatoesStart indoors · Dec 10 – Dec 24
TomatoesTransplant · Feb 11 – Feb 25
Peppers, eggplantStart indoors · Nov 26 – Dec 10
Peppers, eggplantTransplant · Feb 18 – Mar 4
BeansSow outdoors · Feb 11 – Feb 25
Sweet cornSow outdoors · Feb 11 – Feb 25
Cucumbers, squashSow outdoors · Feb 11 – Feb 25
Fall lettuce, spinachSow outdoors · Nov 4 – Nov 18
GarlicPlant cloves · Dec 16 – Jan 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 4) and first fall frost (Dec 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 29403 came on Feb 1 — about the same time as the 1991–2020 average (Jan 30).

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 South Carolina

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

Trees 83

Shrubs 133

Wildflowers & perennials 170

Grasses 169

Vines 12

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 Charleston, SC.

Soil in Charleston, SC

The soil mapped at the center of ZIP 29403 is Yauhannah — loamy fine sand, moderately well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding
pH5.1strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2.25%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Yauhannah-Yemassee-Ogeechee association.

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 29403; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Charleston, SC

Summer high88 °Faverage high, July
Winter low44 °Faverage low, January
Hot days25days a year at 90 °F or more
Freezing nights6nights a year at 32 °F or less
Growing degree days6,519base 50 °F — the season’s usable heat
Longest day14 h 19 mindaylight on June 21
Shortest day9 h 59 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation49.4 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 58 °F, low 44 °F 58°44° JanFebruary: average high 60 °F, low 46 °F 60°46° FebMarch: average high 66 °F, low 52 °F 66°52° MarApril: average high 72 °F, low 60 °F 72°60° AprMay: average high 79 °F, low 68 °F 79°68° MayJune: average high 84 °F, low 74 °F 84°74° JunJuly: average high 88 °F, low 77 °F 88°77° JulAugust: average high 86 °F, low 77 °F 86°77° AugSeptember: average high 83 °F, low 73 °F 83°73° SepOctober: average high 76 °F, low 63 °F 76°63° OctNovember: average high 67 °F, low 53 °F 67°53° NovDecember: average high 61 °F, low 47 °F 61°47° Dec

Precipitation by month inches

0″2″4″6″January: 3.29 in precipitation 3.3 JanFebruary: 3.09 in precipitation 3.1 FebMarch: 3.44 in precipitation 3.4 MarApril: 3.10 in precipitation 3.1 AprMay: 3.08 in precipitation 3.1 MayJune: 5.46 in precipitation 5.5 JunJuly: 5.74 in precipitation 5.7 JulAugust: 6.41 in precipitation 6.4 AugSeptember: 5.54 in precipitation 5.5 SepOctober: 4.06 in precipitation 4.1 OctNovember: 2.73 in precipitation 2.7 NovDecember: 3.42 in precipitation 3.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Charleston City, SC (2 mi away); precipitation: Charleston 2.8 Ne, SC (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Charleston

South Carolina planting zones →

Questions about Charleston

What planting zone is Charleston, SC?

Charleston, SC is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Charleston, SC?

The median last spring frost is February 4 and the median first fall frost is December 30 (NOAA 1991–2020 normals, Charleston City station).

When can I plant a garden in Charleston, SC?

Cool-season crops like peas and spinach go in around Dec 24 – Jan 14; tomatoes, peppers, beans and squash after about Feb 11, once frost risk has passed.

What kind of onions grow in Charleston, SC?

Intermediate onions: the longest day is 14 h 19 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Charleston, SC get?

About 49.4 inches of precipitation a year (NOAA 1991–2020 normals).