Cottage Grove weather in September

In September, Cottage Grove sees average daytime highs of 71°F and overnight lows near 53°F, with 3.3 in of rain across 9.6 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 76°F in the first days to 66°F by the end. The sky is clear or mostly clear about 40% 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 Cottage Grove's 2nd-clearest and 7th-windiest month. For the whole year in context, see Cottage Grove's year-round climate.

Daytime high
71°
4th warmest
Overnight low
53°
9th coldest
Rainfall
3.3 in
9.6 wet days
Daylight
12 h 18 min
5:57 AM – 6:15 PM
Cloud cover
52%
2nd clearest
Wind
8 mph
7th windiest
Solar energy
4.19 kWh/m²
Travel score
6.8
out of 10

Cottage Grove is city in Washington County, Minnesota, United States.

Density
370/km²
people per km²
Founded
1843

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 76°F in the first days to 66°F by the end.

A typical September day in Cottage Grove reaches about 71°F in the afternoon and slips back to 53°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 60°F and 83°F. Set against its neighbours, September runs about 8°F cooler than August and about 14°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17758
27758
37658
47657
57657
67557
77556
87456
97455
107455
117355
127354
137354
147254
157253
167153
177152
187052
197051
206951
216951
226950
236850
246849
256749
266748
276648
286647
296547
306546

How September really feels in Cottage Grove

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.

Cottage Grove weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan23° / 1.06.16.190.0
Feb28° / 12°1.15.25.110.10.0
Mar41° / 24°2.184.211.60.5
Apr55° / 37°3.210.82.313.23.5
May68° / 49°4.412.20.114.65.9
Jun77° / 60°4.412015.36.4
Jul81° / 64°3.610.40156.5
Aug79° / 61°3.910.1013.96.8
Sep71° / 53°3.39.6012.36.8
Oct57° / 40°2.68.70.610.74.2
Nov41° / 27°1.96.73.69.40.5
Dec28° / 15°1.46.76.18.70.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% 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 45%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16139
26238
36238
46139
56139
66040
76139
86040
95941
105842
115743
125743
135545
145446
155446
165248
175248
185248
195248
205149
215149
225149
235149
245149
255149
265149
275248
285248
295248
305248

Chance of precipitation in September

Any precipitation

Cottage Grove gets around 3.3 in of rain over 9.6 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 32% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
130
230
330
430
530
630
730
830
930
1030
1130
1231
1331
1431
1532
1632
1732
1833
1933
2033
2134
2234
2334
2434
2534
2633
2733
2833
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 61% of days. Sticky, muggy-or-worse air turns up on roughly 7% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1362522143
2382421133
3412420132
4432419122
5452319112
6472318102
7492218102
850221792
952221781
1054211681
1155211671
1256211571
1357211561
1458211461
1559211361
1660211351
1762201251
1863201151
1965201041
206719941
216819841
227018831
237217731
247317631
257616530
267815520
278014420
288113420
298312320
308411320

Wind in September

Winds average 8 mph in September.

Across September, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
17calm
27light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze

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 5:39 AM to 6:14 AM, and sunset from 6:44 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:396:44
213.05:406:43
313.05:416:41
412.95:426:39
512.95:436:37
612.85:456:35
712.85:466:33
812.75:476:31
912.75:486:29
1012.65:506:27
1112.65:516:25
1212.55:526:23
1312.55:536:21
1412.45:546:19
1512.45:566:17
1612.35:576:15
1712.35:586:13
1812.25:596:11
1912.16:016:09
2012.16:026:07
2112.06:036:05
2212.06:046:03
2311.96:066:02
2411.96:076:00
2511.86:085:58
2611.86:095:56
2711.76:115:54
2811.76:125:52
2911.66:135:50
3011.66:145:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.19 kWh/m².

For context, solar energy here swings from a low near 1.45 kWh/m² to a high of 6.29 kWh/m² in July across the year — September's 4.19 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.8Bright
44.8Bright
54.7Bright
64.7Bright
74.6Bright
84.6Bright
94.5Bright
104.5Bright
114.4Bright
124.3Bright
134.3Bright
144.2Bright
154.2Bright
164.1Bright
174.0Bright
184.0Bright
194.0Moderate
203.9Moderate
213.9Moderate
223.8Moderate
233.8Moderate
243.8Moderate
253.7Moderate
263.7Moderate
273.6Moderate
283.6Moderate
293.6Moderate
303.5Moderate
Planning a trip in September

Is September a good time to visit Cottage Grove?

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

6.8
Sightseeing
1st-best month of the year
4.5
Beach & pool
4th-best month of the year

September is a reasonable time to visit Cottage Grove for sightseeing.

What to pack for Cottage Grove in September

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

In September, Cottage Grove sees daytime highs around 71°F and nights near 53°F. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Cottage Grove 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 Cottage Grove peaks around June 17 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 12 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 9Jan 12UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr5Moderate
May7Very high
Jun9Very high
Jul8Very high
Aug7Very high
Sep6High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Cottage Grove?

Cottage Grove sits at 44.8°N, 92.9°W, 814 ft above sea level, in United States. The nearest listed city is Inver Grove Heights, 5.0 mi away.

Topography around Cottage Grove

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

Within 2 miles, the terrain around Cottage Grove has only modest variations in elevation — a maximum elevation change of 289 ft around an average of 856 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 486 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 741 ft.

The land around Cottage Grove is covered by trees (42%), grassland (25%) and artificial surfaces (22%) within 2 miles, trees (40%) and cropland (24%) within 10 miles, and cropland (41%) and trees (36%) within 50 miles.

2 miles
289 ft
10 miles
486 ft
50 miles
741 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Inver Grove Heights 5.0 mi · South Saint Paul 6.2 mi · Woodbury 6.8 mi · Hastings 7.5 mi · Maplewood 9.3 mi · Oakdale 9.3 mi · West Saint Paul 9.9 mi · Rosemount 11 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 Cottage Grove (44.8277°, -92.9438°, elevation 814 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. 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).