Charleston, South Carolina climate: Normal weather by month, frost dates and records
Charleston's normal year runs from 39°F January nights to 91°F July afternoons, with 52.5 inches of precipitation and less than an inch of snow (0.3 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 19.2°C, January lows of 4°C, July highs of 33°C, 1,334 mm of precipitation a year.
- NOAA stationCharleston International Airport
- Station IDUSW00013880
- Location32.90°N 80.04°W
- Elevation40 ft (12 m)
- From the center6 miles
- Population157,665
On October 23, the normal high in Charleston is 76°F and the normal low 55°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Charleston.
- Jan 60° 39°
- Feb 64° 42°
- Mar 70° 47°
- Apr 77° 55°
- May 84° 63°
- Jun 89° 70°
- Jul 91° 74°
- Aug 90° 73°
- Sep 85° 68°
- Oct 78° 58°
- Nov 69° 47°
- Dec 63° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Charleston each month?
July is the warmest month, with normal highs of 91°F; January the coldest, with normal lows of 39°F. The most precipitation falls in August (6.97 in), the least in November (2.66 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 60°F | 39°F | 49.5°F | 3.37 | 9 | <1 | 9 | 10 h 10 min |
| February | 64°F | 42°F | 52.7°F | 3.05 | 9 | <1 | 4 | 11 h |
| March | 70°F | 47°F | 58.7°F | 3.35 | 8 | <1 | 2 | 12 h |
| April | 77°F | 55°F | 65.8°F | 3.29 | 8 | 1 | <1 | 13 h |
| May | 84°F | 63°F | 73.3°F | 3.32 | 8 | 5 | <1 | 13 h 50 min |
| June | 89°F | 70°F | 79.4°F | 6.21 | 12 | 14 | <1 | 14 h 20 min |
| July | 91°F | 74°F | 82.5°F | 6.60 | 13 | 21 | <1 | 14 h 10 min |
| August | 90°F | 73°F | 81.4°F | 6.97 | 13 | 17 | <1 | 13 h 20 min |
| September | 85°F | 68°F | 76.9°F | 6.01 | 10 | 6 | <1 | 12 h 30 min |
| October | 78°F | 58°F | 67.8°F | 4.33 | 7 | 1 | <1 | 11 h 30 min |
| November | 69°F | 47°F | 58.3°F | 2.66 | 7 | <1 | 1 | 10 h 30 min |
| December | 63°F | 42°F | 52.2°F | 3.35 | 9 | <1 | 6 | 10 h |
| Year (annual) | 77°F | 56°F | 66.5°F | 52.51 | 114 | 64 | 22 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 16°C | 4°C | 9.7°C | 86 mm |
| February | 18°C | 5°C | 11.5°C | 77 mm |
| March | 21°C | 8°C | 14.8°C | 85 mm |
| April | 25°C | 13°C | 18.8°C | 84 mm |
| May | 29°C | 17°C | 22.9°C | 84 mm |
| June | 31°C | 21°C | 26.3°C | 158 mm |
| July | 33°C | 23°C | 28.1°C | 168 mm |
| August | 32°C | 23°C | 27.4°C | 177 mm |
| September | 30°C | 20°C | 24.9°C | 153 mm |
| October | 26°C | 14°C | 19.9°C | 110 mm |
| November | 21°C | 8°C | 14.6°C | 68 mm |
| December | 17°C | 5°C | 11.2°C | 85 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013880; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Charleston?
Normal highs sit between 65°F and 85°F in March, April, May, October and November. Of those, November has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013880.
When is the last frost in Charleston?
In Charleston, the last spring frost (32°F) comes after March 7 in half of years and after March 27 in one year in ten; the first autumn frost comes before November 27 in half of years and before November 8 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- March 71 year in 10 after March 27; 9 in 10 after February 12
- First autumn frost, half of years before
- November 271 year in 10 before November 8; 9 in 10 before December 21
NOAA puts the median frost-free season at 266 days, and the season without a hard freeze (28°F) at 301 days.
A hard freeze (28°F) comes after February 20 in half of springs and before December 15 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Charleston in zone 9a across its 7 ZIP code areas (9a in 29492, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Charleston's NOAA station is in zone 9a: the coldest night of a typical year reaches 20°F (30 complete years).
Frost dates for every NOAA station in South Carolina · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00013880; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Charleston ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Charleston's 7 ZIP code areas are all in zone 9a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Charleston?
In a normal year in Charleston, 64 days a year reach 90°F (1 of them 100°F or more), 22 nights fall to 32°F or colder and 114 days bring measurable precipitation.
- Days at 90°F or more
- 64a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 22a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 114a normal year
The highest temperature in Charleston's official record (kept by the National Weather Service since 1937) is 105°F, on August 1, 1999; the lowest is 6°F, on January 21, 1985.
The wettest calendar year on that record is 2015, with 74.89 in; the snowiest season is 1989–90, with 8.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00013880; records: ACIS (NOAA Regional Climate Centers), NWS threaded record CHSthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Charleston, and how clear are its skies?
The summer (June-August) dew point averages 72°F. The muggiest month is July, with an average dew point of 73°F, above the 65°F at which most people call the air sticky; the driest air comes in January (38°F). March is the windiest month (9.1 mph on average), and October has the most clear or nearly clear hours (58%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 38°F | 66% | 45% | 8.4 mph | 51% | 30% |
| February | 44°F | 66% | 45% | 8.9 mph | 51% | 26% |
| March | 50°F | 66% | 45% | 9.1 mph | 54% | 20% |
| April | 58°F | 69% | 48% | 8.7 mph | 54% | 16% |
| May | 67°F | 73% | 55% | 8.0 mph | 47% | 15% |
| June | 72°F | 76% | 60% | 7.3 mph | 46% | 12% |
| July | 73°F | 78% | 61% | 7.0 mph | 45% | 12% |
| August | 71°F | 79% | 62% | 7.1 mph | 48% | 15% |
| September | 64°F | 77% | 58% | 7.2 mph | 49% | 20% |
| October | 53°F | 73% | 50% | 7.1 mph | 58% | 19% |
| November | 45°F | 72% | 49% | 7.2 mph | 55% | 20% |
| December | 41°F | 71% | 50% | 7.6 mph | 50% | 27% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00013880. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Charleston?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Charleston, 4.8 kWh per square metre a day. July is the sunniest month (84%) and February the cloudiest (75%). Among the 459 U.S. places of 50,000 or more, that ranks tied 111th (with 13 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 77% | 3.0 |
| February | 75% | 3.6 |
| March | 78% | 4.8 |
| April | 84% | 6.1 |
| May | 84% | 6.5 |
| June | 83% | 6.5 |
| July | 84% | 6.4 |
| August | 82% | 5.7 |
| September | 80% | 4.9 |
| October | 82% | 4.2 |
| November | 81% | 3.3 |
| December | 76% | 2.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Charleston need?
A normal year in Charleston brings 1,844 heating degree days, 66% fewer than the median U.S. place (5,373), and 2,435 cooling degree days, 2.7 times the median (908). Three months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 6,385 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 483 | 4 |
| February | 352 | 7 |
| March | 227 | 31 |
| April | 75 | 99 |
| May | 9 | 266 |
| June | 0 | 434 |
| July | 0 | 542 |
| August | 0 | 510 |
| September | 2 | 357 |
| October | 56 | 143 |
| November | 234 | 32 |
| December | 408 | 9 |
| Year (annual) | 1,844 | 2,435 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013880. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Charleston been warmer than normal lately?
2025 averaged 66.8°F, 0.3°F above the 1991-2020 normal of 66.5°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 66.5°F | at normal | 58.71 |
| 2022 | 67.1°F | +0.6°F | 50.12 |
| 2023 | 68.7°F | +2.2°F | 54.64 |
| 2024 | 68.6°F | +2.1°F | 52.70 |
| 2025 | 66.8°F | +0.3°F | 42.45 |
Over 87 complete years from 1937 to 2025, the station's annual mean temperature rose at a fitted 2.4°F per century (+0.13°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00013880; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Charleston's climate compare?
Charleston is warmer than 70 of the other 72 places with their own NOAA record in South Carolina, and wetter than 53. Across the 7,247 U.S. stations with normals, its annual mean of 66.5°F is warmer than 91%.
In the Köppen classification computed from these normals, Charleston is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Charleston share this climate record?
3 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- North Charleston, SCalso near: Charleston City (12 mi, 67.2°F a year); Summerville (13 mi, 63.8°F a year)126,005 people · 2 mi NW
- Goose Creek, SCalso near: Summerville (13 mi, 63.8°F a year); Charleston City (16 mi, 67.2°F a year)50,352 people · 7 mi N
- Hanahan, SC21,983 people · 3 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Charleston's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Charleston. This page uses Charleston International Airport; the other differs by site and elevation, and the linked ones have pages of their own:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Charleston City USW00013782 | 4 mi SE | 10 ft | 67.2°F | 44°F | 88°F | 44.3 | – | February 4 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Charleston's climate
What is the coldest month in Charleston?
January, with a normal high of 60°F and a normal low of 39°F. The warmest is July (91°F by day, 74°F at night).
Does it snow in Charleston?
Rarely: NOAA's normal is 0.3 inch a year.
What is the rainiest month in Charleston?
August, with 6.97 in of precipitation in a normal year; the driest is November with 2.66 in.
What plant hardiness zone is Charleston in?
The USDA's 2023 map puts Charleston in zone 9a across its 7 ZIP code areas (9a in 29492, the largest). By the same method at Charleston's NOAA station, the coldest night of a typical year reaches 20°F (30 years, 1991-2020): zone 9a.
How late can frost come in Charleston?
In half of years the last 32°F night comes after March 7; in one year in ten it comes after March 27. Waiting until March 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Charleston in OctoberThis month day by day, its records and recent years
- South Carolina climateThe statewide normals and every place in the state
- Charleston City, SC11 miles from this station, 67.2°F a year
- Sullivan's Island, SC14 miles from this station, 65.5°F a year
- Summerville, SC15 miles from this station, 63.8°F a year
- Moncks Corner, SC24 miles from this station, 66.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made