Brookings weather in September

In September, Brookings sees average daytime highs of 71°F and overnight lows near 50°F, with 2.8 in of rain across 7.5 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 76°F in the first days to 66°F by the end. The sky is clear or mostly clear about 48% 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 Brookings's 2nd-clearest and 7th-windiest month. For the whole year in context, see Brookings's year-round climate.

Daytime high
71°
4th warmest
Overnight low
50°
9th coldest
Rainfall
2.8 in
7.5 wet days
Daylight
12 h 18 min
6:12 AM – 6:31 PM
Cloud cover
45%
2nd clearest
Wind
10 mph
7th windiest
Solar energy
4.47 kWh/m²
Travel score
7.2
out of 10

Brookings is city in and county seat of Brookings County, South Dakota, United States.

Density
701/km²
people per km²
Founded
1857

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 Brookings reaches about 71°F in the afternoon and slips back to 50°F overnight — a 21°F spread between the day's warmth and the night's chill. On most days the high lands between 59°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)
17757
27756
37656
47655
57655
67555
77554
87454
97453
107453
117353
127352
137251
147251
157251
167150
177150
187049
197049
206948
216948
226947
236847
246846
256746
266746
276745
286645
296644
306544

How September really feels in Brookings

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.

Brookings 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
Jan23° / 0.854.99.10.0
Feb28° / 11°0.84.54.510.20.0
Mar40° / 22°1.76.43.811.60.5
Apr55° / 34°3.19.72.413.23.5
May67° / 47°3.711.20.114.55.9
Jun77° / 58°4.512.2015.36.5
Jul81° / 62°3.18.70156.9
Aug79° / 59°3.28.4013.87.2
Sep71° / 50°2.87.5012.37.2
Oct57° / 37°2.27.31.110.84.4
Nov41° / 24°1.453.49.40.5
Dec28° / 13°0.94.95.18.70.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 48% 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 37%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16733
26733
36733
46733
56634
66535
76436
86436
96337
106238
116139
126139
136040
146040
156040
166040
176040
186040
196040
206139
216238
226238
236337
246337
256337
266337
276238
286238
296238
306238

Chance of precipitation in September

Any precipitation

Brookings gets around 2.8 in of rain over 7.5 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 26% and peaks near 27% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
124
224
324
425
525
625
725
825
925
1026
1126
1226
1326
1427
1527
1627
1727
1827
1927
2026
2126
2226
2326
2426
2526
2626
2726
2826
2926
3026

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 67% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1412025131
2441924121
3461923111
4481922101
550192290
653182180
755182070
856181970
958181860
1059181760
1162171650
1263171550
1365171440
1466171340
1568171230
1669171130
1770171030
187117930
197316920
207416820
217615720
227715620
238014510
248113510
258312410
268312410
278511310
288710300
29889300
30899200

Wind in September

Winds average 10 mph in September.

Across September, daily wind ranges from about 10 mph on the calmest days to 11 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
610light breeze
710light breeze
810light breeze
910light breeze
1010light breeze
1110light breeze
1210light breeze
1310light breeze
1410light breeze
1510light breeze
1610light breeze
1710light breeze
1810light breeze
1910light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3011light 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 5:55 AM to 6:29 AM, and sunset from 6:59 PM to 6:04 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:556:59
213.05:566:57
313.05:576:56
412.95:586:54
512.95:596:52
612.86:016:50
712.86:026:48
812.76:036:46
912.76:046:44
1012.66:056:42
1112.66:066:40
1212.56:086:38
1312.56:096:36
1412.46:106:34
1512.46:116:33
1612.36:126:31
1712.26:146:29
1812.26:156:27
1912.16:166:25
2012.16:176:23
2112.06:186:21
2212.06:206:19
2311.96:216:17
2411.96:226:15
2511.86:236:13
2611.86:256:11
2711.76:266:09
2811.76:276:07
2911.66:286:05
3011.66:296:04

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.47 kWh/m².

For context, solar energy here swings from a low near 1.64 kWh/m² to a high of 6.64 kWh/m² in July across the year — September's 4.47 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.1Bright
45.1Bright
55.0Bright
65.0Bright
74.9Bright
84.8Bright
94.8Bright
104.7Bright
114.7Bright
124.6Bright
134.5Bright
144.5Bright
154.4Bright
164.4Bright
174.3Bright
184.3Bright
194.2Bright
204.2Bright
214.1Bright
224.1Bright
234.0Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.9Moderate
293.8Moderate
303.8Moderate
Planning a trip in September

Hazard calendar for Brookings

In seasonPeak

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

Brookings's rainy season runs April–October, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Brookings?

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

7.2
Sightseeing
1st-best month of the year
4.8
Beach & pool
4th-best month of the year

September is one of the better times to visit Brookings for general sightseeing.

What to pack for Brookings in September

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

In September, Brookings sees daytime highs around 71°F and nights near 50°F. Little to plan around — just the basics. About 8 days see rain.

UV index in Brookings 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 Brookings peaks around June 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. 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 highHighModerateLowJun 18UV 9Dec 22UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr5High
May6High
Jun9Very high
Jul7Very high
Aug6High
Sep6High
Oct4Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Brookings?

Brookings sits at 44.3°N, 96.8°W, 1,621 ft above sea level, in United States. The nearest listed city is Watertown, 43 mi away.

Topography around Brookings

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

Within 2 miles, the terrain around Brookings has only modest variations in elevation — a maximum elevation change of 118 ft around an average of 1,627 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 246 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 974 ft.

The land around Brookings is covered by grassland (42%) and artificial surfaces (26%) within 2 miles, cropland (63%) and grassland (29%) within 10 miles, and cropland (72%) and grassland (23%) within 50 miles.

2 miles
118 ft
10 miles
246 ft
50 miles
974 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Watertown 43 mi · Sioux Falls 53 mi · Mitchell 74 mi · Willmar 103 mi · Aberdeen 115 mi · Sioux City 127 mi · Mankato 139 mi · Saint Cloud 155 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 Brookings (44.3114°, -96.7984°, elevation 1,621 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).