Charleston weather in August: Charleston, South Carolina: normal highs, lows, rain and records for August
Charleston in August has a normal high of 90°F and a normal low of 73°F, a daily mean of 81°F, falling from 91°F on the 1st to 88°F by the 31st. Measurable precipitation falls on 13 days in a normal August, 6.97 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 32°C and low of 23°C, 177 mm of precipitation in August.
- NOAA stationCharleston International Airport
- Station IDUSW00013880
- Location32.90°N 80.04°W
- Elevation40 ft (12 m)
- From the center6 miles
- Population157,665
- 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.
How warm is Charleston in August?
The normal high is 90°F and the normal low 73°F, for a daily mean of 81.4°F. August is 1.1°F cooler than July and 4.5°F warmer than September. August is the 2nd warmest month of the year in Charleston and the wettest. Across the month the normal high falls 3°F, from 91°F on August 1 to 88°F on August 31. From one year to the next August's mean temperature typically moves about 1.3°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 80°F and 83°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 44%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 91°F | 74°F | 44% | 30% |
| August 8 | 91°F | 74°F | 44% | 30% |
| August 15 | 90°F | 73°F | 43% | 29% |
| August 22 | 89°F | 73°F | 41% | 28% |
| August 31 | 88°F | 72°F | 38% | 26% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 91°F | 74°F | 44% | 30% | 13 h 50 min |
| August 2 | 91°F | 74°F | 44% | 30% | 13 h 50 min |
| August 3 | 91°F | 74°F | 44% | 30% | 13 h 40 min |
| August 4 | 91°F | 74°F | 44% | 30% | 13 h 40 min |
| August 5 | 91°F | 74°F | 44% | 30% | 13 h 40 min |
| August 6 | 91°F | 74°F | 44% | 30% | 13 h 40 min |
| August 7 | 91°F | 74°F | 44% | 30% | 13 h 40 min |
| August 8 | 91°F | 74°F | 44% | 30% | 13 h 40 min |
| August 9 | 91°F | 74°F | 43% | 30% | 13 h 30 min |
| August 10 | 90°F | 74°F | 43% | 30% | 13 h 30 min |
| August 11 | 90°F | 74°F | 43% | 30% | 13 h 30 min |
| August 12 | 90°F | 74°F | 43% | 30% | 13 h 30 min |
| August 13 | 90°F | 74°F | 43% | 30% | 13 h 30 min |
| August 14 | 90°F | 73°F | 43% | 30% | 13 h 30 min |
| August 15 | 90°F | 73°F | 43% | 29% | 13 h 20 min |
| August 16 | 90°F | 73°F | 42% | 29% | 13 h 20 min |
| August 17 | 90°F | 73°F | 42% | 29% | 13 h 20 min |
| August 18 | 90°F | 73°F | 42% | 29% | 13 h 20 min |
| August 19 | 90°F | 73°F | 42% | 29% | 13 h 20 min |
| August 20 | 90°F | 73°F | 41% | 28% | 13 h 20 min |
| August 21 | 89°F | 73°F | 41% | 28% | 13 h 10 min |
| August 22 | 89°F | 73°F | 41% | 28% | 13 h 10 min |
| August 23 | 89°F | 73°F | 40% | 28% | 13 h 10 min |
| August 24 | 89°F | 73°F | 40% | 28% | 13 h 10 min |
| August 25 | 89°F | 72°F | 40% | 27% | 13 h 10 min |
| August 26 | 89°F | 72°F | 39% | 27% | 13 h |
| August 27 | 89°F | 72°F | 39% | 27% | 13 h |
| August 28 | 89°F | 72°F | 39% | 27% | 13 h |
| August 29 | 88°F | 72°F | 39% | 26% | 13 h |
| August 30 | 88°F | 72°F | 38% | 26% | 13 h |
| August 31 | 88°F | 72°F | 38% | 26% | 12 h 50 min |
- Normal high
- 90°FAugust average
- Normal low
- 73°FAugust average
- Precipitation
- 6.97 inmonth total
- Days with precipitation
- 130.01 inch or more
- Days at 90°F or more
- 17
- Daylight
- 13 h 50 min to 12 h 50 minAugust 1 to August 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 30
- Sunshine
- 82%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00013880; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Charleston in August?
On a given August day the chance of 0.01 inch or more is 42% on average, highest around August 1 (44%). In all, 6.97 in falls on 13 days of a normal August, 2 of them with an inch or more.
In a normal August in Charleston, 17 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00013880.
How humid and windy is Charleston in August?
At 3 p.m. the normal temperature is 85°F with 62% relative humidity and a dew point of 71°F; at 6 a.m. it is 73°F with 92% humidity. The wind averages 7.1 mph, most often from the east-southeast in the afternoon. A dew point of 65°F or more feels muggy to most people.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 73°F | 70°F | 92% | 5.4 mph | 51% |
| 9 a.m. | 80°F | 72°F | 76% | 8.0 mph | 43% |
| noon | 85°F | 71°F | 63% | 9.0 mph | 30% |
| 3 p.m. | 85°F | 71°F | 62% | 10.2 mph | 32% |
| 6 p.m. | 81°F | 71°F | 71% | 9.0 mph | 49% |
| 9 p.m. | 77°F | 72°F | 84% | 5.8 mph | 65% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00013880. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for August in Charleston?
The warmest August temperature on Charleston's official record (since 1937) is 105°F, on August 1, 1999; the coldest is 56°F, on August 18, 1979. The wettest August brought 17.24 in (1940).
The August mean against the 1991-2020 normal of 81.4°F: 2021 80.9°F (−0.5), 2022 80.7°F (−0.7), 2023 83.9°F (+2.5), 2024 81.5°F (+0.1), 2025 79.5°F (−1.9), 2026 83.6°F (+2.2). 3 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 80.9°F | −0.5°F | 10.86 in |
| 2022 | 80.7°F | −0.7°F | 9.83 in |
| 2023 | 83.9°F | +2.5°F | 4.97 in |
| 2024 | 81.5°F | +0.1°F | 12.84 in |
| 2025 | 79.5°F | −1.9°F | 11.68 in |
| 2026 | 83.6°F | +2.2°F | 5.43 in |
Source: records: ACIS, NWS threaded record CHSthr; recent months: ACIS, station USW00013880. Records and recent months use complete months only.
How does August in Charleston compare across South Carolina?
Across the 73 places PlainClimate covers in South Carolina, August normal highs run from 76°F in Caesars Head to 92°F in Pelion; Charleston's is 90°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Charleston in July91°F by day, 74°F at night
- Charleston in September85°F by day, 68°F at night
- Charleston through the yearEvery month, frost dates, records and recent years
- South Carolina in AugustThe statewide normal and the warmest and coolest places
- Pelion: South Carolina's warmest Augustnormal high 92°F