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

Planting zone for 29401 — Charleston, SC

ZIP code 29401 (Charleston, Charleston County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 4 and the first fall frost December 30.

Where ZIP 29401 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 frostFeb 4
First frostDec 30
2012 zone9a

Same zone as on the 2012 map. 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 Charleston, SC…

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 — within 1 mile, 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 29401

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 29401 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

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 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 133

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 170

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 speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 169

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 12

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °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 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °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 Charleston, SC.

Soil in Charleston, SC

The soil mapped at the center of ZIP 29401 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 29401; 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
Precipitation44.3 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: 2.56 in precipitation 2.6 JanFebruary: 2.56 in precipitation 2.6 FebMarch: 3.03 in precipitation 3.0 MarApril: 2.96 in precipitation 3.0 AprMay: 2.58 in precipitation 2.6 MayJune: 4.85 in precipitation 4.8 JunJuly: 5.08 in precipitation 5.1 JulAugust: 6.11 in precipitation 6.1 AugSeptember: 5.25 in precipitation 5.3 SepOctober: 4.07 in precipitation 4.1 OctNovember: 2.30 in precipitation 2.3 NovDecember: 2.91 in precipitation 2.9 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

294029a
Charleston, SC · <1 mi
294039a
Charleston, SC · 2 mi
294079a
Charleston, SC · 4 mi
294659a
Mount Pleasant, SC · 4 mi
294129a
Charleston, SC · 5 mi
294649a
Mount Pleasant, SC · 5 mi
294829a
Sullivans Island, SC · 6 mi
294059a
North Charleston, SC · 6 mi

All 13 ZIP codes in Charleston → · South Carolina planting zones →

Questions about 29401

What planting zone is ZIP code 29401?

ZIP code 29401 (Charleston, SC) 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 Charleston, SC?

The median last spring frost (32 °F) near 29401 is February 4; after March 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Charleston City station.

When is the first frost in Charleston, SC?

The median first fall frost near 29401 is December 30, giving a median frost-free growing season of 321 days.

When should I plant tomatoes in 29401?

Start tomato seeds indoors around Dec 10 – Dec 24 and set transplants outside around Feb 11 – Feb 25, one to three weeks after the median last frost.

How much rain and snow does 29401 get?

About 44.3 inches of precipitation a year (NOAA 1991–2020 normals, Charleston City station).

How hot do summers get in Charleston, SC?

The average high peaks at 88 °F in July, with about 25 days a year at 90 °F or more.

What kind of soil does 29401 have?

The USDA soil survey maps Yauhannah at the center of ZIP 29401: loamy fine sand, moderately well drained, pH about 5.1 (strongly acidic).

Did spring come early in Charleston, SC in 2026?

Spring leaf-out near 29401 came on Feb 1 in 2026, about the same as the 1991–2020 average (Jan 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Charleston, SC?

Intermediate onions: the longest day near 29401 is 14 h 19 min, so day-neutral types bulb best; long-day varieties may not bulb fully.