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

Planting zone for 29422 — Charleston, SC

ZIP code 29422 (Charleston, Charleston County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 13 and the first fall frost November 30.

Where ZIP 29422 is

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 13
First frostNov 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 frostMarch 13median — 50% chance of a later frost
Safe for tender plantsMarch 30only 10% chance of frost after
First fall frostNovember 30median — 10% chance by Nov 11
Growing season262 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 1 and returns around December 16.

From the NOAA station Sullivans Is, SC — 6 miles away, elevation 7 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 29422

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 30 – Feb 13
SpinachSow outdoors · Jan 30 – Feb 20
Broccoli, cabbageStart indoors · Jan 2 – Jan 16
Broccoli, cabbageTransplant · Feb 20 – Mar 6
Onion setsPlant outdoors · Feb 13 – Feb 27
PotatoesPlant outdoors · Feb 20 – Mar 6
LettuceSow outdoors · Feb 13 – Feb 27
Carrots, beetsSow outdoors · Feb 20 – Mar 6
TomatoesStart indoors · Jan 16 – Jan 30
TomatoesTransplant · Mar 20 – Apr 3
Peppers, eggplantStart indoors · Jan 2 – Jan 16
Peppers, eggplantTransplant · Mar 27 – Apr 10
BeansSow outdoors · Mar 20 – Apr 3
Sweet cornSow outdoors · Mar 20 – Apr 3
Cucumbers, squashSow outdoors · Mar 20 – Apr 3
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 13) 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 29422 came on Feb 7 — 8 days later than 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 29422 is Charleston — loamy fine sand, moderately well drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding
pH4.7strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Charleston loamy fine sand.

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 29422; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Charleston, SC

Summer high91 °Faverage high, July
Winter low37 °Faverage low, January
Hot days55days a year at 90 °F or more
Freezing nights18nights a year at 32 °F or less
Growing degree days6,058base 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
Precipitation54.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 59 °F, low 37 °F 59°37° JanFebruary: average high 61 °F, low 39 °F 61°39° FebMarch: average high 67 °F, low 45 °F 67°45° MarApril: average high 75 °F, low 54 °F 75°54° AprMay: average high 82 °F, low 63 °F 82°63° MayJune: average high 88 °F, low 70 °F 88°70° JunJuly: average high 91 °F, low 73 °F 91°73° JulAugust: average high 90 °F, low 72 °F 90°72° AugSeptember: average high 86 °F, low 68 °F 86°68° SepOctober: average high 78 °F, low 58 °F 78°58° OctNovember: average high 69 °F, low 47 °F 69°47° NovDecember: average high 62 °F, low 40 °F 62°40° Dec

Precipitation by month inches

0″2″4″6″8″January: 3.38 in precipitation 3.4 JanFebruary: 3.29 in precipitation 3.3 FebMarch: 3.64 in precipitation 3.6 MarApril: 3.76 in precipitation 3.8 AprMay: 3.54 in precipitation 3.5 MayJune: 5.63 in precipitation 5.6 JunJuly: 6.44 in precipitation 6.4 JulAugust: 7.65 in precipitation 7.7 AugSeptember: 6.16 in precipitation 6.2 SepOctober: 4.22 in precipitation 4.2 OctNovember: 2.83 in precipitation 2.8 NovDecember: 3.77 in precipitation 3.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sullivans Is, SC (6 mi away); precipitation: Mount Pleasant 1.0 Wsw, SC (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

294139a
Charleston, SC · <1 mi
294169a
Charleston, SC · <1 mi
294179a
Charleston, SC · <1 mi
294239a
Charleston, SC · <1 mi
294649a
Mount Pleasant, SC · 2 mi
294659a
Mount Pleasant, SC · 4 mi
294929a
Charleston, SC · 4 mi
294669a
Mount Pleasant, SC · 5 mi

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

Questions about 29422

What planting zone is ZIP code 29422?

ZIP code 29422 (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 29422 is March 13; after March 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sullivans Is station.

When is the first frost in Charleston, SC?

The median first fall frost near 29422 is November 30, giving a median frost-free growing season of 262 days.

When should I plant tomatoes in 29422?

Start tomato seeds indoors around Jan 16 – Jan 30 and set transplants outside around Mar 20 – Apr 3, one to three weeks after the median last frost.

How much rain and snow does 29422 get?

About 54.3 inches of precipitation a year (NOAA 1991–2020 normals, Mount Pleasant 1.0 Wsw station).

How hot do summers get in Charleston, SC?

The average high peaks at 91 °F in July, with about 55 days a year at 90 °F or more.

What kind of soil does 29422 have?

The USDA soil survey maps Charleston at the center of ZIP 29422: loamy fine sand, moderately well drained, pH about 4.7 (strongly acidic).

Did spring come early in Charleston, SC in 2026?

Spring leaf-out near 29422 came on Feb 7 in 2026, 8 days later than 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 29422 is 14 h 19 min, so day-neutral types bulb best; long-day varieties may not bulb fully.