Bangor weather in September

In September, Bangor sees average daytime highs of 69°F and overnight lows near 50°F, with 3.5 in of rain across 8.4 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 74°F in the first days to 64°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 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Bangor's 1st-clearest and 9th-windiest month. For the whole year in context, see Bangor's year-round climate.

Daytime high
69°
4th warmest
Overnight low
50°
9th coldest
Rainfall
3.5 in
8.4 wet days
Daylight
12 h 18 min
5:20 AM – 5:39 PM
Cloud cover
56%
1st clearest
Wind
7 mph
9th windiest
Solar energy
4.01 kWh/m²
Travel score
6.7
out of 10

Bangor is city in and county seat of Penobscot County, Maine, United States.

Density
362/km²
people per km²
Founded
1769

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 74°F in the first days to 64°F by the end.

A typical September day in Bangor reaches about 69°F in the afternoon and slips back to 50°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 61°F and 79°F. Set against its neighbours, September runs about 8°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17455
27455
37454
47354
57354
67353
77253
87253
97253
107152
117152
127152
137051
147051
156951
166950
176950
186850
196849
206849
216749
226748
236648
246648
256647
266547
276547
286446
296446
306446

How September really feels in Bangor

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.

Bangor weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan28° / 11°3.49.16.990.0
Feb31° / 13°2.997.310.10.0
Mar39° / 22°3.610.46.311.60.2
Apr52° / 34°3.611.22.713.22.6
May63° / 44°3.311.30.114.65.3
Jun73° / 53°3.711.4015.36.3
Jul78° / 59°3.110.60156.5
Aug77° / 58°3.09.5013.96.9
Sep69° / 50°3.58.4012.36.7
Oct57° / 40°4.410.60.510.74.0
Nov45° / 30°3.79.82.69.40.9
Dec34° / 19°4.311.578.70.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September, the clearest month of the year.

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 (%)
15446
25446
35347
45347
55248
65347
75248
85248
95248
105248
115149
125248
135248
145149
155149
165149
175050
185050
194951
204951
214951
224951
234951
244951
254951
264852
274852
284753
294852
304753

Chance of precipitation in September

Any precipitation

Bangor gets around 3.5 in of rain over 8.4 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 33% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
126
226
326
427
527
627
727
828
928
1028
1128
1228
1327
1427
1527
1627
1727
1827
1928
2028
2128
2228
2329
2429
2530
2631
2731
2832
2933
3033

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 65% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
14924208
25023198
35123197
45223187
55323177
65423176
75523166
85623165
95723155
105823154
115823154
125923144
136122143
146122143
156421132
166421132
176520132
186819121
196819121
206918121
217017121
227216111
237216111
247415101
25771490
26771490
27791380
28811270
29811270
30831160

Wind in September

Winds average 7 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 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 90 minutes over September. Sunrise moves from 5:02 AM to 5:38 AM, and sunset from 6:08 PM to 5:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:026:08
213.05:036:06
313.05:046:04
412.95:066:02
512.95:076:00
612.85:085:58
712.85:095:56
812.75:105:54
912.75:125:52
1012.65:135:50
1112.65:145:48
1212.55:155:46
1312.55:175:45
1412.45:185:43
1512.45:195:41
1612.35:205:39
1712.35:215:37
1812.25:235:35
1912.15:245:33
2012.15:255:31
2112.05:265:29
2212.05:285:27
2311.95:295:25
2411.95:305:23
2511.85:315:21
2611.85:335:19
2711.75:345:17
2811.75:355:15
2911.65:365:13
3011.65:385:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.01 kWh/m².

For context, solar energy here swings from a low near 1.39 kWh/m² to a high of 5.74 kWh/m² in July across the year — September's 4.01 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.6Bright
34.6Bright
44.5Bright
54.5Bright
64.5Bright
74.4Bright
84.4Bright
94.3Bright
104.3Bright
114.2Bright
124.2Bright
134.1Bright
144.1Bright
154.0Bright
164.0Bright
174.0Moderate
183.9Moderate
193.9Moderate
203.8Moderate
213.8Moderate
223.7Moderate
233.7Moderate
243.6Moderate
253.6Moderate
263.5Moderate
273.5Moderate
283.4Moderate
293.4Moderate
303.3Moderate
Planning a trip in September

Hazard calendar for Bangor

In seasonPeak

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

Bangor 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 Bangor?

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

6.7
Sightseeing
2nd-best month of the year
3.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Bangor for sightseeing.

What to pack for Bangor in September

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

In September, Bangor sees daytime highs around 69°F and nights near 50°F. Worth packing: rain gear. About 8 days see rain.

rain gear

Sea temperature near Bangor in September

The nearest coast averages about 57°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 30 mi away) is warmest in August at about 58°F and coldest in February near 35°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

30°40°50°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan39Bracing
Feb35Bracing
Mar35Bracing
Apr40Bracing
May46Bracing
Jun52Bracing
Jul57Bracing
Aug58Bracing
Sep57Bracing
Oct54Bracing
Nov49Bracing
Dec44Bracing

UV index in Bangor in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bangor peaks around July 13 at about 7 (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 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateModerateLowJul 13UV 7Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5Moderate
May7High
Jun6High
Jul8Very high
Aug4Moderate
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Bangor?

Bangor sits at 44.8°N, 68.8°W, 118 ft above sea level, in United States. The nearest listed city is Bar Harbor, 40 mi away.

Topography around Bangor

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

Within 2 miles, the terrain around Bangor has only modest variations in elevation — a maximum elevation change of 266 ft around an average of 118 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 912 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,870 ft.

The land around Bangor is covered by trees (51%) and artificial surfaces (23%) within 2 miles, trees (78%) within 10 miles, and trees (80%) within 50 miles.

2 miles
266 ft
10 miles
912 ft
50 miles
1,870 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Bar Harbor 40 mi · Waterville 45 mi · Augusta 60 mi · Brunswick 85 mi · Lewiston 86 mi · Auburn 87 mi · Portland 108 mi · South Portland 108 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 Bangor (44.7988°, -68.7726°, elevation 118 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).