Clemson weather in September

In September, Clemson sees average daytime highs of 82°F and overnight lows near 64°F, with 3.4 in of rain across 8.5 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 85°F in the first days to 78°F by the end. The sky is clear or mostly clear about 38% of the time in September, and the air most often feels muggy.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Clemson's 3rd-clearest and 9th-windiest month. For the whole year in context, see Clemson's year-round climate.

Daytime high
82°
4th warmest
Overnight low
64°
9th coldest
Rainfall
3.4 in
8.5 wet days
Daylight
12 h 12 min
6:19 AM – 6:32 PM
Cloud cover
53%
3rd clearest
Wind
5 mph
9th windiest
Solar energy
4.6 kWh/m²
Travel score
6.4
out of 10

Clemson is city in South Carolina, United States.

Density
758/km²
people per km²

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 85°F in the first days to 78°F by the end.

A typical September day in Clemson reaches about 82°F in the afternoon and slips back to 64°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 74°F and 90°F. Set against its neighbours, September runs about 6°F cooler than August and about 10°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18568
28567
38567
48567
58567
68466
78466
88466
98466
108365
118365
128365
138364
148264
158264
168264
178263
188163
198163
208062
218062
228062
237961
247961
257961
267860
277860
287859
297759
307759

How September really feels in Clemson

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.

Clemson weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan52° / 34°4.810.10.99.92.8
Feb56° / 36°4.29.20.810.73.7
Mar63° / 42°4.910.10.211.75.6
Apr72° / 50°3.98.8012.86.8
May79° / 59°3.29.4013.86.8
Jun85° / 67°3.412.1014.34.9
Jul89° / 71°3.312.7014.14.0
Aug87° / 70°3.912.2013.34.4
Sep82° / 64°3.48.5012.26.4
Oct72° / 52°3.46.9011.17.3
Nov62° / 42°4.08.5010.25.6
Dec54° / 36°4.79.30.59.73.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 44%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15446
25446
35545
45545
55545
65545
75743
85743
95743
105743
115743
125743
135644
145644
155644
165545
175545
185446
195446
205446
215446
225545
235545
245545
255644
265644
275644
285644
295644
305743

Chance of precipitation in September

Any precipitation

Clemson gets around 3.4 in of rain over 8.5 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 28% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
132
231
331
430
529
629
728
827
927
1026
1126
1226
1326
1426
1526
1627
1727
1828
1928
2028
2129
2229
2328
2428
2528
2627
2727
2826
2926
3026

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 29% of days. Sticky, muggy-or-worse air turns up on roughly 37% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1311264119
2412264018
3513273917
4514283716
5615283615
6716293514
7816293413
8917293311
91018303310
10111830329
11121829328
12131929328
13141929317
14151929316
15161929306
16171929296
17171929295
18181930285
19191930275
20201930264
21211930264
22231929254
23241929244
24261929233
25281928213
26292028203
27312028192
28322027182
29342126172
30362126162

Wind in September

Winds average 5 mph in September.

Across September, daily wind ranges from about 4 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 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 66 minutes over September. Sunrise moves from 6:08 AM to 6:30 AM, and sunset from 6:54 PM to 6:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:086:54
212.76:096:53
312.76:106:51
412.76:106:50
512.66:116:48
612.66:126:47
712.56:136:45
812.56:136:44
912.56:146:42
1012.46:156:41
1112.46:166:39
1212.46:166:38
1312.36:176:37
1412.36:186:35
1512.36:196:34
1612.26:196:32
1712.26:206:31
1812.16:216:29
1912.16:216:28
2012.16:226:26
2112.06:236:25
2212.06:246:23
2312.06:246:22
2411.96:256:20
2511.96:266:19
2611.86:276:17
2711.86:286:16
2811.86:286:14
2911.76:296:13
3011.76:306:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.6 kWh/m².

For context, solar energy here swings from a low near 2.31 kWh/m² to a high of 6.16 kWh/m² in June across the year — September's 4.6 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
74.9Bright
84.9Bright
94.9Bright
104.8Bright
114.8Bright
124.8Bright
134.7Bright
144.7Bright
154.7Bright
164.6Bright
174.6Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.4Bright
234.3Bright
244.3Bright
254.3Bright
264.2Bright
274.2Bright
284.2Bright
294.2Bright
304.1Bright
Planning a trip in September

Hazard calendar for Clemson

In seasonPeak

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

Clemson 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 Clemson?

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

6.4
Sightseeing
4th-best month of the year
7.0
Beach & pool
1st-best month of the year

September is a reasonable time to visit Clemson for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Clemson in September

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

In September, Clemson sees daytime highs around 82°F and nights near 64°F. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Clemson in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Clemson peaks around July 10 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 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 10UV 10Dec 20UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7High
May8Very high
Jun10Very high
Jul10Very high
Aug8Very high
Sep7High
Oct5Moderate
Nov4Moderate
Dec2Moderate

Air quality in Clemson 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 Clemson is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (January, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodJul 1718 µg/m³Jan 118 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb10Good
Mar12Moderate
Apr11Good
May13Moderate
Jun16Moderate
Jul19Moderate
Aug16Moderate
Sep12Moderate
Oct9Good
Nov10Good
Dec8Good
Location & terrain

Where is Clemson?

Clemson sits at 34.7°N, 82.8°W, 725 ft above sea level, in United States. The nearest listed city is Anderson, 16 mi away.

Topography around Clemson

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

Within 2 miles, the terrain around Clemson has only modest variations in elevation — a maximum elevation change of 295 ft around an average of 738 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 771 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,070 ft.

The land around Clemson is covered by trees (54%) and water (20%) within 2 miles, trees (67%) within 10 miles, and trees (82%) within 50 miles.

2 miles
295 ft
10 miles
771 ft
50 miles
6,070 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Anderson 16 mi · Easley 17 mi · Greenville 28 mi · Mauldin 30 mi · Wade Hampton 32 mi · Simpsonville 34 mi · Taylors 35 mi · Greer 39 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 Clemson (34.6834°, -82.8374°, elevation 725 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). 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).