Hottest (avg)
#2 / 12
One of the warmer months.
August in context
How it compares to the rest of the year in Charleston.
Wettest (avg)
#1 / 12
The wettest month of the year.
Daylight Hours
#4 / 12
Around the yearly average.
Windiest (avg)
#12 / 12
Usually calmer than most months.
Highest UV
#4 / 12
Near the middle of the yearly UV range.
Most Humid
#1 / 12
The muggiest month of the year.
Monthly climate breakdown
A detailed look at the typical climate conditions for August.
Thermal profile
Temperature
Typical daytime high
- Nighttime low
-
- Feels like (avg)
-
Light window
Sunshine
13.3 h
Average daylight
- UV index (max)
- 8
- Typical sun hours
- 05:43 - 19:02
Wet-day pattern
Rain & Snow
Typical rainfall
- Rainy days
- 22 days
- Cloud cover (avg)
- 59%
Air feel
Humidity & Wind
82%
Average humidity
- Wind (avg)
-
- Wind (max gusts)
-
Historical daily baseline
Daily climate explorer
Pick a day to inspect the usual conditions through August in Charleston. Based on a 30-year historical climate baseline, not a forecast.
Primary control
Select a day
Scroll to compare daily conditions. The summary updates with your selection.
Secondary context
Monthly trend
Median daytime highs across the month, with a softer low line.
Median temperatureMedian lowTypical range
Day 15 selected for August. Temperature 29.3°C.
Historical disruption baseline
Typical disruptions in August
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in August.
Humidity High impact
Muggy days Measures: Muggy days (dew point >=20C). Observed about 94% of days (29.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
29.3 days / month
- Share of days
- ~94% of days
- Upper edge
- Up to ~25°C (P95)
Why this matters
Muggy conditions are possible on ~29 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat High impact
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 82% of days (25.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
25.5 days / month
- Share of days
- ~82% of days
- Upper edge
- Up to ~40°C (P95)
Why this matters
Feels-like heat >=32C is possible on ~25 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Very hot feels-like Measures: Very hot feels-like days (>=35C). Observed about 48% of days (14.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
14.8 days / month
- Share of days
- ~48% of days
- Upper edge
- Up to ~40°C (P95)
Why this matters
Very hot feels-like conditions are possible on ~15 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Heat stress risk Measures: High heat stress days. Observed about 48% of days (14.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
14.8 days / month
- Share of days
- ~48% of days
- Upper edge
- Up to ~40°C (P95)
Why this matters
Heat stress is possible on ~15 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Hot days Measures: Hot days (>=30C). Observed about 39% of days (12.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
12.2 days / month
- Share of days
- ~39% of days
- Upper edge
- Up to ~34°C (P95)
Why this matters
Hot days are possible on ~12 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Humidity High impact
Oppressive humidity Measures: Oppressive humidity days (dew point >=24C). Observed about 38% of days (11.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
11.8 days / month
- Share of days
- ~38% of days
- Upper edge
- Up to ~26°C (P95)
Why this matters
Oppressive humidity is possible on ~12 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Show all disruptions (26 more)
Rain High impact
Rain disruption Measures: Likely rain disruption days. Observed about 31% of days (9.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
9.5 days / month
- Share of days
- ~31% of days
- Upper edge
- Up to ~37mm (P95)
Why this matters
Rain disruption risk appears on ~9 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout risk Measures: Washout day risk. Observed about 27% of days (8.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
8.5 days / month
- Share of days
- ~27% of days
- Upper edge
- Up to ~42mm (P95)
Why this matters
Washout conditions are possible on ~8 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 16% of days (4.9 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
4.9 days / month
- Share of days
- ~16% of days
- Upper edge
- Up to ~47mm (P95)
Why this matters
Heavy rain is possible on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 2.1 days/month in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.1 days / month
- Share of days
- —
- Upper edge
- Up to ~46mm (P95)
Why this matters
Multi-day washout runs are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 4% of days (1.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.1 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~67mm (P95)
Why this matters
Very heavy rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Stormy conditions Measures: Storm-impact proxy days. Observed about 2% of days (0.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.6 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~91km/h (P95)
Why this matters
Stormy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 2% of days (0.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.6 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~92km/h (P95)
Why this matters
Strong gusts are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain High impact
Extreme rain Measures: Extreme rain days (>=50mm). Observed about 1% of days (0.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~109mm (P95)
Why this matters
Extreme rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat Moderate
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 2.3 days/month in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.3 days / month
- Share of days
- —
- Upper edge
- Up to ~39°C (P95)
Why this matters
Feels-like heatwave runs are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat Moderate
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 1.8 days/month in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.8 days / month
- Share of days
- —
- Upper edge
- Up to ~34°C (P95)
Why this matters
Heatwave runs are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Visibility Moderate
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 4% of days (1.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.2 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~94% (P95)
Why this matters
Fog-likely conditions are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
Humid days Measures: Humid days (dew point >=18C). Observed about 99% of days (30.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
30.6 days / month
- Share of days
- ~99% of days
- Upper edge
- Up to ~25°C (P95)
Why this matters
Humid conditions are possible on ~31 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Heat Minor
Warm nights Measures: Warm nights (min >=22C). Observed about 94% of days (29.0 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
29.0 days / month
- Share of days
- ~94% of days
- Upper edge
- Up to ~27°C (P95)
Why this matters
Warm nights are possible on ~29 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 82% of days (25.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
25.4 days / month
- Share of days
- ~82% of days
- Upper edge
- Up to ~23mm (P95)
Why this matters
Measurable rain is possible on ~25 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 70% of days (21.7 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
21.7 days / month
- Share of days
- ~70% of days
- Upper edge
- Up to ~91% (P95)
Why this matters
High humidity is possible on ~22 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 66% of days (20.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
20.6 days / month
- Share of days
- ~66% of days
- Upper edge
- Up to ~19h (P95)
Why this matters
Several rainy hours are possible on ~21 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 53% of days (16.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
16.5 days / month
- Share of days
- ~53% of days
- Upper edge
- Up to ~99% (P95)
Why this matters
Cloudy skies are possible on ~16 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 45% of days (13.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
13.8 days / month
- Share of days
- ~45% of days
- Upper edge
- Up to ~21h (P95)
Why this matters
Wet-most-of-day conditions are possible on ~14 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat Minor
Hot nights Measures: Hot nights (min >=25C). Observed about 36% of days (11.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
11.2 days / month
- Share of days
- ~36% of days
- Upper edge
- Up to ~27°C (P95)
Why this matters
Hot nights are possible on ~11 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Humidity Minor
Convective risk Measures: Convective storm risk proxy. Observed about 31% of days (9.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
9.5 days / month
- Share of days
- ~31% of days
- Upper edge
- Up to ~25°C (P95)
Why this matters
Convective risk signal appears on ~9 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 27% of days (8.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
8.5 days / month
- Share of days
- ~27% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Mostly cloudy skies are possible on ~8 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 19% of days (5.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.8 days / month
- Share of days
- ~19% of days
- Upper edge
- Up to ~66km/h (P95)
Why this matters
Gusty conditions are possible on ~6 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 10% of days (3.0 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.0 days / month
- Share of days
- ~10% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Overcast skies are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Other Minor
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 4% of days (1.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.2 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~94 (P95)
Why this matters
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 1% of days (0.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.4 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~31km/h (P95)
Why this matters
Breezy conditions are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Heat Minor
Very hot days Measures: Very hot days (>=35C). Observed about 1% of days (0.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~36°C (P95)
Why this matters
Very hot days are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Travel planning FAQ
Frequently asked questions
Quick answers to the weather questions you ask the most.
Is August a good time to visit Charleston?
Typical August days in Charleston reach highs of 30°C (86°F) with nights around 24°C (75°F). It usually feels hot by day and warm after dark. It is among the wetter months, so it is wise to have some indoor backup plans or flexible activities.
What are temperatures like in August?
Daytime temperatures in August typically peak near 30°C (86°F), while nights drop to around 24°C (75°F). Expect hot afternoons and warm evenings.
How much does it rain in August?
Rainfall in August averages 161 mm (6.3 in) across roughly 22 days. Overall it is a very wet time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in August?
You can expect about 13 hours of daylight in August. Sunrise is typically around 05:43 and sunset near 19:02. You get long days with comfortable amounts of daylight.
How strong is the sun in August?
UV levels frequently reach very high levels (around 8), so strong sun protection is essential, especially around midday.
Is it windy in August?
In August, average wind speeds are around 11 km/h (7 mph), with gusts on the windiest days reaching about 44 km/h (27 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.