Superior weather in September

In September, Superior sees average daytime highs of 66°F and overnight lows near 56°F, with 3.6 in of rain across 10.7 wet days and about 12.4 hours of daylight. It is the 3rd-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 71°F in the first days to 61°F by the end. The sky is clear or mostly clear about 33% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Superior's 3rd-clearest and 4th-windiest month. For the whole year in context, see Superior's year-round climate.

Daytime high
66°
3rd warmest
Overnight low
56°
10th coldest
Rainfall
3.6 in
10.7 wet days
Daylight
12 h 18 min
5:53 AM – 6:13 PM
Cloud cover
57%
3rd clearest
Wind
11 mph
4th windiest
Solar energy
3.88 kWh/m²
Travel score
5.9
out of 10

Superior is city in and county seat of Douglas County, Wisconsin, United States.

Density
185/km²
people per km²
Founded
1854

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 71°F in the first days to 61°F by the end.

A typical September day in Superior reaches about 66°F in the afternoon and slips back to 56°F overnight — a 10°F spread between the day's warmth and the night's chill. On most days the high lands between 57°F and 75°F. Set against its neighbours, September runs about 7°F cooler than August and about 14°F warmer than October.

40°50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
17262
27162
37161
47161
57061
67060
77060
86960
96959
106959
116858
126858
136758
146757
156757
166656
176656
186556
196555
206455
216454
226454
236354
246353
256253
266252
276152
286151
296051
306050

How September really feels in Superior

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.

Superior 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
Jan19° / 1.06.36.98.80.0
Feb22° / 10°1.15.35.6100.0
Mar31° / 20°1.97.35.111.60.0
Apr41° / 31°3.310.24.213.30.4
May53° / 42°3.811.10.514.82.9
Jun65° / 55°4.111.6015.65.5
Jul73° / 64°3.911.7015.36.7
Aug73° / 64°4.010.50146.9
Sep66° / 56°3.610.7012.45.9
Oct52° / 44°4.110.80.810.62.8
Nov38° / 30°2.68.959.20.1
Dec26° / 17°1.87.47.88.40.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% 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 49%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25941
35941
45842
55743
65743
75644
85644
95545
105446
115347
125248
135248
145149
155149
165050
174951
184951
194753
204852
214852
224753
234753
244753
254654
264654
274654
284654
294654
304555

Chance of precipitation in September

Any precipitation

Superior gets around 3.6 in of rain over 10.7 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 36% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
132
232
332
432
532
632
732
833
933
1033
1134
1234
1335
1435
1536
1636
1737
1838
1938
2039
2139
2239
2339
2439
2539
2638
2738
2837
2937
3036

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 62% of days. Sticky, muggy-or-worse air turns up on roughly 6% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1362624122
2382523122
3402522122
4422421111
5452420111
6462319101
7482318101
850221891
951221791
1054211681
1155211680
1257211570
1358201570
1460201460
1561201450
1662201350
1765191240
1866191140
1967191130
2069181030
217217920
227317820
237516720
247715620
257914610
268014510
278213410
288312410
298511310
308610310

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
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 5:33 AM to 6:12 AM, and sunset from 6:43 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:336:43
213.15:346:41
313.15:366:39
413.05:376:37
513.05:386:35
612.95:406:33
712.85:416:31
812.85:426:29
912.75:446:27
1012.75:456:25
1112.65:466:23
1212.65:486:21
1312.55:496:19
1412.45:506:17
1512.45:526:15
1612.35:536:13
1712.35:546:11
1812.25:566:08
1912.25:576:06
2012.15:586:04
2112.06:006:02
2212.06:016:00
2311.96:025:58
2411.96:045:56
2511.86:055:54
2611.86:065:52
2711.76:085:50
2811.66:095:48
2911.66:105:46
3011.56:125:44

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.88 kWh/m².

For context, solar energy here swings from a low near 1.21 kWh/m² to a high of 6.06 kWh/m² in July across the year — September's 3.88 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.5Bright
44.5Bright
54.4Bright
64.4Bright
74.3Bright
84.3Bright
94.2Bright
104.1Bright
114.1Bright
124.0Bright
134.0Moderate
143.9Moderate
153.9Moderate
163.8Moderate
173.8Moderate
183.7Moderate
193.7Moderate
203.6Moderate
213.6Moderate
223.5Moderate
233.5Moderate
243.4Moderate
253.4Moderate
263.3Moderate
273.3Moderate
283.3Moderate
293.2Moderate
303.2Moderate
Planning a trip in September

Is September a good time to visit Superior?

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

5.9
Sightseeing
3rd-best month of the year
2.6
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Superior for sightseeing.

What to pack for Superior in September

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

In September, Superior sees daytime highs around 66°F and nights near 56°F. Worth packing: rain gear. About 11 days see rain.

rain gear

Sea temperature near Superior in September

The nearest coast averages about 58°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 63°F and coldest in February near 34°F.

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

30°40°50°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°F)Comfort
Jan36Bracing
Feb34Bracing
Mar34Bracing
Apr36Bracing
May38Bracing
Jun44Bracing
Jul55Bracing
Aug63Cool
Sep58Bracing
Oct50Bracing
Nov43Bracing
Dec38Bracing

UV index in Superior 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 Superior peaks around June 17 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 11 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 highHighModerateLowJun 17UV 8Jan 11UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May6High
Jun8Very high
Jul7High
Aug7High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Superior?

Superior sits at 46.7°N, 92.1°W, 643 ft above sea level, in United States. The nearest listed city is Duluth, 4.3 mi away.

Topography around Superior

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

Within 2 miles, the terrain around Superior has only modest variations in elevation — a maximum elevation change of 118 ft around an average of 630 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 1,322 ft.

The land around Superior is covered by artificial surfaces (33%), water (22%) and trees (21%) within 2 miles, trees (53%) and water (28%) within 10 miles, and trees (77%) within 50 miles.

2 miles
118 ft
10 miles
912 ft
50 miles
1,322 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Duluth 4.3 mi · Hibbing 63 mi · Forest Lake 108 mi · Ham Lake 116 mi · Andover 117 mi · Lino Lakes 117 mi · Ramsey 120 mi · Stillwater 120 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 Superior (46.7208°, -92.1041°, elevation 643 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. 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).