New London weather in September

In September, New London sees average daytime highs of 69°F and overnight lows near 62°F, with 4.1 in of rain across 8.8 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 72°F in the first days to 66°F by the end. The sky is clear or mostly clear about 42% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is New London's 3rd-clearest and 8th-windiest month. For the whole year in context, see New London's year-round climate.

Daytime high
69°
3rd warmest
Overnight low
62°
10th coldest
Rainfall
4.1 in
8.8 wet days
Daylight
12 h 18 min
5:35 AM – 5:51 PM
Cloud cover
52%
3rd clearest
Wind
11 mph
8th windiest
Solar energy
4.43 kWh/m²
Travel score
6.8
out of 10

New London is city in Connecticut, United States.

Density
989/km²
people per km²
Founded
1646

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 72°F in the first days to 66°F by the end.

A typical September day in New London reaches about 69°F in the afternoon and slips back to 62°F overnight — a 7°F spread between the day's warmth and the night's chill. On most days the high lands between 65°F and 74°F. Set against its neighbours, September runs about 5°F cooler than August and about 8°F warmer than October.

50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
17366
27366
37265
47265
57265
67265
77265
87164
97164
107164
117164
127164
137063
147063
157063
167062
176962
186962
196962
206961
216861
226861
236861
246860
256760
266760
276759
286659
296659
306658

How September really feels in New London

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.

New London weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 29°4.010.44.59.40.0
Feb38° / 29°3.69.1410.30.0
Mar43° / 34°4.710.53.411.70.4
Apr50° / 43°4.210.90.413.12.3
May58° / 51°3.510.8014.34.3
Jun67° / 61°3.69.6014.96.3
Jul74° / 68°3.08.7014.77.2
Aug74° / 68°3.88.8013.77.2
Sep69° / 62°4.18.8012.36.8
Oct61° / 53°4.89.40.110.95.3
Nov52° / 44°4.29.30.39.72.8
Dec44° / 35°4.911.52.89.10.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 42% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 43%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25941
35842
45941
55842
65842
75941
85941
95941
105941
115842
125842
135842
145842
155842
165743
175743
185644
195644
205446
215446
225545
235446
245446
255446
265446
275446
285446
295446
305644

Chance of precipitation in September

Any precipitation

New London gets around 4.1 in of rain over 8.8 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 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
126
226
326
426
527
627
727
827
927
1028
1128
1228
1328
1428
1528
1628
1728
1829
1929
2030
2130
2230
2331
2431
2531
2632
2732
2832
2932
3032

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 32% of days. Sticky, muggy-or-worse air turns up on roughly 23% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1132229297
2142228287
3152228287
4172228277
5182227267
6192227266
7202227256
8222226255
9232226245
10242225245
11262225244
12272125234
13292124233
14302124223
15312124212
16332123212
17342123201
18352123191
19362123191
20372123181
21392123170
22402122170
23412122160
24422122150
25442121140
26452121130
27462121120
28482120110
29492120100
30502119100

Wind in September

Winds average 11 mph in September.

Across September, daily wind ranges from about 10 mph on the calmest days to 12 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
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours 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 84 minutes over September. Sunrise moves from 5:19 AM to 5:49 AM, and sunset from 6:17 PM to 5:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:196:17
212.95:206:16
312.95:216:14
412.85:226:12
512.85:236:10
612.75:246:09
712.75:256:07
812.65:266:05
912.65:276:03
1012.65:286:02
1112.55:296:00
1212.55:305:58
1312.45:315:56
1412.45:325:54
1512.35:345:53
1612.35:355:51
1712.25:365:49
1812.25:375:47
1912.15:385:46
2012.15:395:44
2112.05:405:42
2212.05:415:40
2311.95:425:38
2411.95:435:37
2511.85:445:35
2611.85:455:33
2711.85:465:31
2811.75:475:30
2911.75:485:28
3011.65:495:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.43 kWh/m².

For context, solar energy here swings from a low near 1.69 kWh/m² to a high of 6.35 kWh/m² in June across the year — September's 4.43 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.0Bright
35.0Bright
44.9Bright
54.9Bright
64.8Bright
74.8Bright
84.8Bright
94.7Bright
104.7Bright
114.6Bright
124.6Bright
134.6Bright
144.5Bright
154.5Bright
164.4Bright
174.4Bright
184.4Bright
194.3Bright
204.3Bright
214.2Bright
224.2Bright
234.1Bright
244.1Bright
254.0Bright
264.0Moderate
273.9Moderate
283.9Moderate
293.8Moderate
303.8Moderate
Planning a trip in September

Hazard calendar for New London

In seasonPeak

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

New London 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 New London?

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

6.8
Sightseeing
3rd-best month of the year
4.1
Beach & pool
3rd-best month of the year

September is a reasonable time to visit New London for sightseeing.

What to pack for New London in September

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

In September, New London sees daytime highs around 69°F and nights near 62°F. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near New London in September

The nearest coast averages about 68°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 16 mi away) is warmest in August at about 71°F and coldest in February near 39°F.

It's comfortable for a long swim from Jul 15 to Sep 15 — about 2.1 months when the water holds above 68°F.

40°50°60°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan42Bracing
Feb39Bracing
Mar39Bracing
Apr44Bracing
May52Bracing
Jun61Cool
Jul69Refreshing
Aug71Refreshing
Sep68Refreshing
Oct63Cool
Nov55Bracing
Dec48Bracing

UV index in New London 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 New London peaks around July 10 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 10UV 8Dec 22UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in New London 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 New London is worst in July — around 15 µg/m³ PM2.5 (moderate), about 2.6× the cleanest month (November, 6 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1515 µg/m³Nov 206 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb10Good
Mar11Good
Apr12Good
May14Moderate
Jun14Moderate
Jul15Moderate
Aug13Moderate
Sep10Good
Oct7Good
Nov6Good
Dec6Good
Location & terrain

Where is New London?

New London sits at 41.4°N, 72.1°W, 56 ft above sea level, in United States. The nearest listed city is Waterford, 1.9 mi away.

Topography around New London

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

Within 2 miles, the terrain around New London has only modest variations in elevation — a maximum elevation change of 266 ft around an average of 82 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 656 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,325 ft.

The land around New London is covered by trees (41%) and artificial surfaces (29%) within 2 miles, trees (55%) and water (35%) within 10 miles, and trees (49%) and water (44%) within 50 miles.

2 miles
266 ft
10 miles
656 ft
50 miles
1,325 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Waterford 1.9 mi · Ledyard 7.5 mi · Montville Center 8.7 mi · Norwich 12 mi · Westerly 14 mi · Windham 24 mi · Plainfield 24 mi · Willimantic 25 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 New London (41.3556°, -72.0995°, elevation 56 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).