Charleston climate
Charleston (South Carolina, United States) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 19 °C66 °F, and about 1,246 mm49 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Charleston climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 1457 | 439 | 948 | 612.4 | 7 |
| Feb | 1661 | 642 | 1152 | 853.3 | 3 |
| Mar | 2067 | 948 | 1458 | 843.3 | 1 |
| Apr | 2475 | 1356 | 1966 | 823.2 | 0 |
| May | 2883 | 1864 | 2374 | 923.6 | 0 |
| Jun | 3188 | 2272 | 2780 | 1405.5 | 0 |
| Jul | 3290 | 2475 | 2882 | 1475.8 | 0 |
| Aug | 3188 | 2374 | 2781 | 1706.7 | 0 |
| Sep | 2984 | 2169 | 2577 | 1194.7 | 0 |
| Oct | 2577 | 1559 | 2068 | 1054.1 | 0 |
| Nov | 2067 | 949 | 1458 | 692.7 | 1 |
| Dec | 1661 | 644 | 1152 | 923.6 | 3 |
| Year | 3290 | 439 | 1966 | 1,24649 | 15 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 80% | 68% | 2.8 | 10:13 |
| Feb | 80% | 70% | 3.4 | 10:58 |
| Mar | 78% | 60% | 4.6 | 11:53 |
| Apr | 75% | 48% | 6.0 | 12:57 |
| May | 73% | 49% | 6.5 | 13:50 |
| Jun | 76% | 57% | 6.5 | 14:18 |
| Jul | 76% | 58% | 6.3 | 14:06 |
| Aug | 79% | 60% | 5.7 | 13:21 |
| Sep | 80% | 58% | 4.8 | 12:19 |
| Oct | 78% | 50% | 4.1 | 11:18 |
| Nov | 79% | 55% | 3.1 | 10:25 |
| Dec | 82% | 67% | 2.5 | 10:00 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Charleston is like
The warmest month is July, with an average high of 32 °C90 °F and a low of 24 °C75 °F. The coldest is January, when highs average 14 °C57 °F and lows 4 °C39 °F. Seasons are strongly marked: the warmest month is on average 18.8 °C33.8 °F warmer than the coldest.
It is wet, with about 1,246 mm49 in of precipitation per year. The wettest three-month stretch is June–August, which brings 37% of the annual total. The wettest month is August (170 mm6.7 in), the driest is January (61 mm2.4 in).
Relative humidity ranges from 73% in May to 82% in December. The clearest skies (lowest average cloud amount, 48%) are typical of April. Average wind speed near the ground ranges from 4 km/h (3 mph) in August to 5 km/h (3 mph) in February. Daylight lasts from about 10.0 hours in December to 14.3 hours in June.
Best time to visit Charleston
Based on these averages, the most comfortable months for sightseeing and outdoor activities are March–May and October and November: average highs of 20 °C67 °F to 28 °C83 °F with 69 mm2.7 in to 105 mm4.1 in of precipitation per month.
The most challenging month is August, which is hot, with average highs of 31 °C88 °F, very wet (170 mm6.7 in) and humid (79% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Charleston
- Winter (December–February) — highs 1457 to 16 °C61 °F, lows 439 to 6 °C44 °F, about 79 mm3.1 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
- Spring (March–May) — highs 2067 to 28 °C83 °F, lows 948 to 18 °C64 °F, about 86 mm3.4 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 3188 to 32 °C90 °F, lows 2272 to 24 °C75 °F, about 153 mm6.0 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and an umbrella or light rain jacket.
- Autumn (September–November) — highs 2067 to 29 °C84 °F, lows 949 to 21 °C69 °F, about 98 mm3.8 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an umbrella or light rain jacket.
How Charleston compares
Compared with Savannah, about 134 km to the southwest, Charleston is on average 0.8 °C1.4 °F cooler and receives 8% more precipitation (1,246 mm49 in vs 1,152 mm45 in). The difference is largest in March (1 °C1.9 °F cooler).
Of the 222 places in the United States covered by World Climates, Charleston is the 50th warmest by annual mean temperature and the 47th wettest by annual precipitation. See all of them on the United States climate page.
Places in other countries with the most similar temperature and rainfall pattern: Wenzhou (China, Cfa), Fuding (China, Cfa) and Songcheng (China, Cfa).
The same NASA POWER grid cell also contains North Charleston (pop. 108,304). Their long-term averages in this dataset are essentially the same as for Charleston, so they do not have separate pages.
Nearby places
- Savannah 134 km · 20 °C68 °F · 1,152 mm45 in
- Columbia 170 km · 18 °C64 °F · 1,150 mm45 in
- Wilmington 245 km · 19 °C65 °F · 1,374 mm54 in
- Fayetteville 271 km · 17 °C62 °F · 1,237 mm49 in
- Charlotte 285 km · 16 °C60 °F · 1,146 mm45 in
- Jacksonville 317 km · 21 °C69 °F · 1,285 mm51 in
- Athens 346 km · 17 °C62 °F · 1,261 mm50 in
- High Point 354 km · 15 °C58 °F · 1,147 mm45 in
Frequently asked questions
What is the warmest month in Charleston?
July is the warmest month in Charleston, with an average high of 32 °C (90 °F) and an average low of 24 °C (75 °F).
What is the coldest month in Charleston?
January is the coldest month, with an average high of 14 °C (57 °F) and an average low of 4 °C (39 °F).
When does it rain the most in Charleston?
August is the wettest month with about 170 mm (6.7 in) of precipitation; January is the driest with about 61 mm (2.4 in).
What is the best time to visit Charleston?
Judging by long-term averages, the most comfortable months are March–May and October and November.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.