Mount Pleasant weather in September

In September, Mount Pleasant sees average daytime highs of 80°F and overnight lows near 74°F, with 6.1 in of rain across 14.2 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 82°F in the first days to 78°F by the end. The sky is clear or mostly clear about 40% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 42 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Mount Pleasant's 7th-clearest and 9th-windiest month. For the whole year in context, see Mount Pleasant's year-round climate.

Daytime high
80°
4th warmest
Overnight low
74°
9th coldest
Rainfall
6.1 in
14.2 wet days
Daylight
12 h 12 min
6:08 AM – 6:20 PM
Cloud cover
54%
7th clearest
Wind
11 mph
9th windiest
Solar energy
4.77 kWh/m²
Travel score
6.0
out of 10

Mount Pleasant is town in Charleston County, South Carolina, United States.

Density
696/km²
people per km²
Founded
1680

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 82°F in the first days to 78°F by the end.

A typical September day in Mount Pleasant reaches about 80°F in the afternoon and slips back to 74°F overnight — a 6°F spread between the day's warmth and the night's chill. On most days the high lands between 76°F and 83°F. Set against its neighbours, September runs about 3°F cooler than August and about 6°F warmer than October.

60°70°80°151015202530
Avg high (°F)Avg low (°F)
18277
28276
38276
48276
58276
68176
78176
88176
98175
108175
118175
128175
138075
148075
158074
168074
178074
188074
198074
207974
217973
227973
237973
247973
257873
267872
277872
287872
297871
307871

How September really feels in Mount Pleasant

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Mount Pleasant weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan58° / 49°3.79.610.14.5
Feb59° / 50°3.8910.84.7
Mar63° / 55°3.58.311.86.0
Apr69° / 62°3.0712.87.0
May75° / 69°2.58.213.77.3
Jun81° / 76°4.613.914.15.9
Jul84° / 78°4.91513.95.0
Aug83° / 78°6.518.213.24.8
Sep80° / 74°6.114.212.26.0
Oct74° / 66°4.58.611.27.3
Nov66° / 57°3.07.510.36.6
Dec61° / 52°4.09.69.95.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15149
25248
35347
45347
55446
65545
75644
85644
95644
105842
115842
125842
135842
145842
155842
165842
175842
185842
195743
205743
215644
225644
235644
245545
255644
265644
275644
285644
295545
305545

Chance of precipitation in September

Any precipitation

Mount Pleasant gets around 6.1 in of rain over 14.2 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 46% and peaks near 53% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
153
252
351
451
550
650
749
849
949
1048
1148
1248
1347
1447
1546
1646
1746
1845
1945
2045
2145
2244
2344
2443
2543
2642
2741
2841
2940
3040

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the oppressive band about 51% of days. Sticky, muggy-or-worse air turns up on roughly 83% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1013145725
2014145724
3014155723
4025165621
5025165720
6026175619
7026185717
8027185716
9038195515
10038205514
11039205513
120310215412
130310215511
140311225410
15041222539
16141222529
17141223528
18141323518
19151323517
20151323517
21251423506
22261423496
23361423485
24371423475
25471524465
26581524444
27581525434
28691525414
29691526403
30791626393

Wind in September

Winds average 11 mph in September.

Across September, daily wind ranges from about 10 mph on the calmest days to 11 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
110light breeze
210light breeze
310light breeze
410light breeze
510light breeze
611light breeze
711light breeze
811light breeze
911light breeze
1011light breeze
1111light breeze
1211light breeze
1311light breeze
1411light breeze
1511light breeze
1611light breeze
1711light breeze
1811light breeze
1911light breeze
2011light breeze
2111light breeze
2211light breeze
2311light breeze
2411light breeze
2511light breeze
2611light breeze
2711light breeze
2811light breeze
2911light breeze
3011light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 42 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over September. Sunrise moves from 5:58 AM to 6:17 AM, and sunset from 6:40 PM to 6:00 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:586:40
212.75:596:39
312.65:596:38
412.66:006:36
512.66:016:35
612.56:016:34
712.56:026:32
812.56:036:31
912.46:036:30
1012.46:046:28
1112.46:046:27
1212.36:056:25
1312.36:066:24
1412.36:066:23
1512.26:076:21
1612.26:086:20
1712.26:086:18
1812.16:096:17
1912.16:106:16
2012.16:106:14
2112.06:116:13
2212.06:126:11
2312.06:126:10
2411.96:136:08
2511.96:146:07
2611.96:156:06
2711.86:156:04
2811.86:166:03
2911.76:176:02
3011.76:176:00

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.77 kWh/m².

For context, solar energy here swings from a low near 2.61 kWh/m² to a high of 6.54 kWh/m² in May across the year — September's 4.77 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.1Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
104.9Bright
114.9Bright
124.9Bright
134.9Bright
144.8Bright
154.8Bright
164.8Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.6Bright
224.6Bright
234.6Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.4Bright
294.4Bright
304.4Bright
Planning a trip in September

Hazard calendar for Mount Pleasant

In seasonPeak

In September, Mount Pleasant sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Mount Pleasant sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Mount Pleasant?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.0
Sightseeing
5th-best month of the year
6.0
Beach & pool
4th-best month of the year

September is a reasonable time to visit Mount Pleasant for sightseeing.

What to pack for Mount Pleasant in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Mount Pleasant sees daytime highs around 80°F and nights near 74°F. Pack rain gear. Worth having: light clothes and sun protection. About 14 days see rain.

rain gearlight clothessun protection

Sea temperature near Mount Pleasant in September

The nearest coast averages about 81°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 12 mi away) is warmest in August at about 83°F and coldest in February near 60°F.

It's comfortable for a long swim from Apr 25 to Nov 19 — about 6.9 months when the water holds above 68°F.

60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan61Cool
Feb60Cool
Mar61Cool
Apr66Cool
May73Refreshing
Jun80Warm
Jul83Tropical
Aug83Tropical
Sep81Warm
Oct75Warm
Nov68Refreshing
Dec64Cool

UV index in Mount Pleasant in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mount Pleasant peaks around July 13 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJul 13UV 10Dec 19UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar7High
Apr7Very high
May8Very high
Jun9Very high
Jul10Very high
Aug9Very high
Sep8Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Mount Pleasant in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Mount Pleasant is worst in March — around 21 µg/m³ PM2.5 (moderate), about 3.5× the cleanest month (December, 6 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodMar 1719 µg/m³Dec 136 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb12Moderate
Mar21Moderate
Apr12Moderate
May11Good
Jun14Moderate
Jul16Moderate
Aug14Moderate
Sep9Good
Oct6Good
Nov7Good
Dec6Good
Location & terrain

Where is Mount Pleasant?

Mount Pleasant sits at 32.8°N, 79.9°W, 10 ft above sea level, in United States. The nearest listed city is Charleston, 4.3 mi away.

Topography around Mount Pleasant

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Mount Pleasant.

Within 2 miles, the terrain around Mount Pleasant has only modest variations in elevation — a maximum elevation change of 66 ft around an average of 16 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 131 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 226 ft.

The land around Mount Pleasant is covered by trees (42%), water (20%) and wetland (20%) within 2 miles, water (44%) and trees (27%) within 10 miles, and trees (50%) and water (38%) within 50 miles.

2 miles
66 ft
10 miles
131 ft
50 miles
226 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Charleston 4.3 mi · North Charleston 7.5 mi · Hanahan 12 mi · Goose Creek 16 mi · Summerville 24 mi · Hilton Head 65 mi · Hilton Head Island 66 mi · Bluffton 70 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Mount Pleasant (32.7941°, -79.8626°, elevation 10 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).