Charleston, South Carolina Weather
Thunder quiets the land. Day 93 of summer. Read this microseason across nine climate regions →
Charleston weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 10:27 AM EDT · Open-Meteo
- TodaySep 21Overcast later16%—86°76°—
- TuesdaySep 22Overcast37%—84°74°-2°
- WednesdaySep 23Light Drizzle53%—88°72°+4°
- ThursdaySep 24Showers14%—74°65°-14°
- FridaySep 25Mostly Clear——80°59°+6°
- SaturdaySep 26Overcast——80°57°0°
- SundaySep 27Overcast——81°61°+1°
Air quality now AQI 32 · Good
AQI 32 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 7.7 µg/m³ (AQI 43) with a 0.79 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in stagnant air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 8 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 35. Overcast through the UV peak window (cloud cover ~77%) — afternoon ozone should stay flat.
- Present
- AQI 35
- UV peak
- 4.2 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 10
PM × Wind × Precip
PM2.5 at 7.7 µg/m³ (AQI 43) with a 0.79 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.79
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:33 PM
- Moonset
- 2:01 AM
- In sign
- ♑︎ Capricorn
Thunder quiets the land
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Charleston at a glance
- Today vs. normal: Today averages 81°F (high 86°F, low 76°F), 6°F above the 75°F normal for Sep 21
- Last frost: February 4 (1991–2020 median, NOAA station 5 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant tomatoes, peppers, beans, squash; harvest tomatoes, peppers, beans, summer squash, winter squash
16-Day Forecast — Charleston
- Mon86°76°16%
- Tue84°74°37%
- Wed88°72°53%
- Thu74°65°14%
- Fri80°59°4%
- Sat80°57°4%
- Sun81°61°4%
- Mon82°64°6%
- Tue82°71°12%
- Wed83°69°21%
- Thu86°71°19%
- Fri86°70°25%
- Sat82°75°24%
- Sun85°74°35%
- Mon82°70°26%
- Tue73°60°23%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Charleston
Interactive wind and temperature map centered on Charleston — it loads in your browser. Open the full weather map.
Right now in the garden
Peak growing season
As of September 21, the growing season is at its peak — the first frost (around December 30) is weeks away. Fall transplants go in about 10–12 weeks before the first frost, October 7 to October 21 here. This city's planting calendar for September: plant tomatoes, peppers, beans, and squash; harvest tomatoes, peppers, beans, summer squash, and winter squash.
SPC Convective Outlook
Storm Prediction Center — Charleston
SPC includes Charleston in the general thunderstorm area today — no severe risk, but storms are possible.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook.
Sun & seasons in Charleston
Charleston sits in Charleston County, where the year’s longest day runs 14h 19m of daylight and its shortest just 9h 59m — a swing of +4h 20m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Charleston is the state’s largest city. The nearest town Charleston tracks is Edisto, roughly 71 miles to the NW.
Air quality in Charleston
Air quality in Charleston’s county has held roughly steady since 2020; its cleanest year on record was 2020 (median AQI 43). See the full air-quality history for Charleston.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | lettuce, peas, spinach, radishes | fall brassicas, carrots |
| February | lettuce, peas, spinach, radishes | lettuce, spinach, radishes |
| March | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| April | tomatoes, peppers, beans, squash | lettuce, peas, spinach |
| May | beans, squash | peas, beans, summer squash, garlic |
| June | beans, squash | tomatoes, peppers, beans, summer squash |
| July | beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| August | beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| September | tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, winter squash |
| October | beans, squash, fall brassicas, carrots | beans, summer squash, winter squash |
| November | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| December | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
A year in weather
July is Charleston's warmest stretch (~81°F) and January its coldest (~51°F); precipitation crests in August at 6.8 inches and ebbs in April to 2.5 inches.
| Month | Mean temp | Precip |
|---|---|---|
| January | 51° | 4.0″ |
| February | 53° | 3.4″ |
| March | 58° | 4.0″ |
| April | 65° | 2.5″ |
| May | 73° | 2.7″ |
| June | 79° | 4.4″ |
| July | 81° | 6.3″ |
| August | 81° | 6.8″ |
| September | 77° | 5.0″ |
| October | 70° | 2.7″ |
| November | 60° | 2.5″ |
| December | 54° | 3.3″ |
Regional context
Similar climates James Island, SC, Hanahan, SC, Sullivan's Island, SC
Charleston's climate, from modelled 1991-2020 normals (EC_Earth3P_HR model via Open-Meteo), pairs 51°F Januarys with 81°F Julys — a 30°F swing. About 47.6 inches of precipitation falls each year.
Charleston gets its most rain in August, 6.8 inches, and its least in April, 2.5 inches, though May through September is wetter overall than November through March. The closest comparisons in South Carolina are places like James Island, SC, Hanahan, SC and Sullivan's Island, SC.
The cool-season window in Charleston starts at February 4, when nights stop freezing — think lettuce, chard, arugula, and mustard greens. Warm-soil crops in Charleston wait about two weeks past Charleston's last frost, once the soil warms. It shuts near December 30, when freezes return to Charleston and tender plants need cover. Sheltered Charleston yards can escape a light frost.
Similar climates: James Island, SC, Hanahan, SC, Sullivan's Island, SC, North Charleston, SC, Mount Pleasant, SC.
Frequently asked
- When does it freeze in Charleston?
- Frost typically leaves Charleston by February 4 and returns to Charleston near December 30.
- What is the rainy season in Charleston?
- Charleston sees its heaviest rain in August (around 6.8 inches), part of roughly 48 inches a year.
- What is the warmest month in Charleston?
- Charleston peaks in July, when the mean runs near 81°F.
- What is the coldest month in Charleston?
- January is Charleston's coldest month, averaging about 51°F.
- When can I start a vegetable garden in Charleston?
- Around February 4, start frost-hardy crops in Charleston; tomatoes and basil belong a fortnight later.
- What hardiness zone is Charleston?
- Because Charleston bottoms near 51°F in January, that winter low sets Charleston's USDA zone — verify by ZIP.
- What is the 10-day forecast for Charleston?
- Charleston's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Charleston?
- See this week's day-by-day rain chances for Charleston in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Charleston?
- Current conditions for Charleston and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Charleston forecast updated?
- The Charleston forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Charleston?
- Today's sunrise and sunset times for Charleston are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Charleston?
- The next few days in Charleston's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Charleston sits at 32.8°N; its climate zone is humid subtropical (Köppen approximation).
ZIP codes in Charleston
- 29401
- 29402
- 29403
- 29405
- 29406
- 29407
- 29409
- 29412
- 29413
- 29414
- 29417
- 29422
- 29424
- 29425
- 29455
- 29457
- 29492