Somerset weather in September

In September, Somerset sees average daytime highs of 76°F and overnight lows near 60°F, with 4.0 in of rain across 9.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 81°F in the first days to 72°F by the end. The sky is clear or mostly clear about 35% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Somerset's 2nd-clearest and 9th-windiest month. For the whole year in context, see Somerset's year-round climate.

Daytime high
76°
4th warmest
Overnight low
60°
9th coldest
Rainfall
4.0 in
9.1 wet days
Daylight
12 h 18 min
5:44 AM – 6:00 PM
Cloud cover
56%
2nd clearest
Wind
6 mph
9th windiest
Solar energy
4.18 kWh/m²
Travel score
6.9
out of 10

Somerset is community in Franklin Township, New Jersey, United States.

Density
1,319/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 81°F in the first days to 72°F by the end.

A typical September day in Somerset reaches about 76°F in the afternoon and slips back to 60°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 67°F and 85°F. Set against its neighbours, September runs about 7°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18164
28164
38164
48064
58064
68063
78063
87963
97962
107862
117862
127861
137761
147760
157760
167660
177659
187659
197558
207558
217558
227458
237457
247357
257356
267356
277256
287255
297255
307155

How September really feels in Somerset

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.

Somerset weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 26°3.39.24.19.40.0
Feb42° / 27°3.08.53.510.40.4
Mar50° / 34°4.210.52.911.72.3
Apr62° / 44°3.710.70.3135.0
May71° / 54°3.611.4014.26.3
Jun81° / 63°4.211.2014.86.0
Jul86° / 69°4.211.2014.64.9
Aug83° / 67°4.110.2013.65.8
Sep76° / 60°4.09.1012.36.9
Oct65° / 49°3.78.60.110.96.1
Nov54° / 38°3.07.90.49.73.4
Dec44° / 31°4.09.42.29.20.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 49%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15149
25248
35248
45149
55149
65149
75149
85149
95149
105149
115149
125149
135248
145149
155149
165050
175149
185050
195050
205050
214951
224951
235050
245050
254951
265050
275050
285050
295149
305248

Chance of precipitation in September

Any precipitation

Somerset gets around 4.0 in of rain over 9.1 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 29% and peaks near 30% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
127
227
327
428
528
628
729
829
929
1029
1129
1229
1329
1429
1529
1629
1729
1829
1930
2030
2130
2230
2330
2430
2530
2630
2730
2830
2930
3030

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 40% of days. Sticky, muggy-or-worse air turns up on roughly 20% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
12322232210
22422232110
32523222010
42523222010
52623221910
62723211810
72824211710
8292421179
9302420169
10322420168
11332420158
12342420157
13352420157
14372320146
15382320145
16402319145
17412219134
18422219134
19442119133
20452118133
21472118123
22482017122
23492017122
24512016112
25522016111
26551915101
27551915101
28551915101
2958181491
3058181491

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 5:29 AM to 5:59 AM, and sunset from 6:26 PM to 5:36 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:296:26
212.95:306:24
312.95:316:23
412.85:326:21
512.85:336:19
612.75:346:18
712.75:356:16
812.65:366:14
912.65:376:12
1012.55:386:11
1112.55:396:09
1212.45:406:07
1312.45:416:05
1412.45:426:04
1512.35:436:02
1612.35:446:00
1712.25:455:58
1812.25:465:57
1912.15:475:55
2012.15:485:53
2112.05:495:51
2212.05:505:50
2311.95:515:48
2411.95:525:46
2511.95:535:45
2611.85:545:43
2711.85:565:41
2811.75:575:39
2911.75:585:38
3011.65:595:36

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.18 kWh/m².

For context, solar energy here swings from a low near 1.77 kWh/m² to a high of 5.97 kWh/m² in June across the year — September's 4.18 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.6Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.5Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.2Bright
164.2Bright
174.1Bright
184.1Bright
194.1Bright
204.0Bright
214.0Moderate
223.9Moderate
233.9Moderate
243.9Moderate
253.8Moderate
263.8Moderate
273.7Moderate
283.7Moderate
293.7Moderate
303.6Moderate
Planning a trip in September

Hazard calendar for Somerset

In seasonPeak

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

Somerset 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 Somerset?

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

6.9
Sightseeing
1st-best month of the year
6.1
Beach & pool
4th-best month of the year

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

What to pack for Somerset in September

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

In September, Somerset sees daytime highs around 76°F and nights near 60°F. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Somerset in September

The nearest coast averages about 71°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 34 mi away) is warmest in August at about 74°F and coldest in February near 40°F.

It's comfortable for a long swim from Jun 30 to Sep 27 — about 3 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan43Bracing
Feb40Bracing
Mar41Bracing
Apr46Bracing
May55Bracing
Jun65Cool
Jul72Refreshing
Aug74Refreshing
Sep71Refreshing
Oct64Cool
Nov55Bracing
Dec49Bracing

UV index in Somerset in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Somerset peaks around July 11 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 21 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 8Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov3Moderate
Dec1Low

Air quality in Somerset 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 Somerset is worst in July — around 18 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (November, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJul 1318 µg/m³Nov 1410 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar16Moderate
Apr16Moderate
May17Moderate
Jun17Moderate
Jul18Moderate
Aug16Moderate
Sep14Moderate
Oct11Good
Nov10Good
Dec12Good
Location & terrain

Where is Somerset?

Somerset sits at 40.5°N, 74.5°W, 92 ft above sea level, in United States. The nearest listed city is New Brunswick, 1.9 mi away.

Topography around Somerset

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

Within 2 miles, the terrain around Somerset has only modest variations in elevation — a maximum elevation change of 197 ft around an average of 98 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 659 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,781 ft.

The land around Somerset is covered by trees (58%) and artificial surfaces (27%) within 2 miles, trees (60%) and artificial surfaces (20%) within 10 miles, and trees (58%) within 50 miles.

2 miles
197 ft
10 miles
659 ft
50 miles
1,781 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: New Brunswick 1.9 mi · North Brunswick 3.1 mi · Edison 4.3 mi · Piscataway 5.0 mi · East Brunswick 6.2 mi · South River 6.2 mi · South Plainfield 6.8 mi · Sayreville 7.5 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 Somerset (40.4976°, -74.4885°, elevation 92 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).