Bourbonnais weather in September

In September, Bourbonnais sees average daytime highs of 76°F and overnight lows near 56°F, with 3.0 in of rain across 8.3 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 80°F in the first days to 71°F by the end. The sky is clear or mostly clear about 43% 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 Bourbonnais's 1st-clearest and 9th-windiest month. For the whole year in context, see Bourbonnais's year-round climate.

Daytime high
76°
4th warmest
Overnight low
56°
9th coldest
Rainfall
3.0 in
8.3 wet days
Daylight
12 h 18 min
5:38 AM – 5:54 PM
Cloud cover
49%
1st clearest
Wind
7 mph
9th windiest
Solar energy
4.55 kWh/m²
Travel score
7.1
out of 10

Bourbonnais is village in Kankakee County, Illinois, United States of America.

Density
757/km²
people per km²
Founded
1832

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 80°F in the first days to 71°F by the end.

A typical September day in Bourbonnais reaches about 76°F in the afternoon and slips back to 56°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 65°F and 86°F. Set against its neighbours, September runs about 6°F cooler than August and about 13°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18062
28061
38061
48060
58060
67960
77959
87959
97859
107858
117858
127757
137757
147756
157656
167656
177655
187555
197555
207454
217454
227453
237353
247353
257352
267252
277251
287151
297151
307150

How September really feels in Bourbonnais

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.

Bourbonnais 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
Jan32° / 19°2.48.65.39.40.0
Feb37° / 22°2.07.34.210.40.0
Mar49° / 31°3.010.12.511.71.9
Apr61° / 41°4.312.10.713.14.7
May71° / 52°4.612.9014.36.1
Jun80° / 62°4.212.2014.96.1
Jul83° / 66°3.611.2014.75.7
Aug82° / 64°3.59.7013.66.5
Sep76° / 56°3.08.3012.37.1
Oct63° / 44°3.29.10.110.95.7
Nov49° / 34°2.88.61.29.72.1
Dec37° / 24°2.28.33.59.10.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25941
36040
46040
55941
66040
76040
86040
96040
105941
115941
125842
135842
145743
155644
165644
175545
185545
195545
205446
215446
225446
235446
245446
255347
265347
275347
285347
295347
305446

Chance of precipitation in September

Any precipitation

Bourbonnais gets around 3.0 in of rain over 8.3 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 30% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
129
229
329
429
529
629
730
830
930
1030
1130
1230
1330
1430
1530
1629
1729
1829
1928
2028
2128
2227
2327
2427
2527
2627
2728
2828
2928
3027

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 47% of days. Sticky, muggy-or-worse air turns up on roughly 14% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1202524238
2222524227
3232623217
4252723206
5262722195
6282822175
7302821164
8322821154
9342820153
10362820143
11382719142
12402619132
13422618132
14442518122
15462417121
16482416111
17502315111
18532214101
19542213101
20562112101
2160201190
2262191090
236419980
246518980
256618970
266917860
276917860
287116850
297215850
307415740

Wind in September

Winds average 7 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
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167light breeze
177light 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 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 5:22 AM to 5:52 AM, and sunset from 6:20 PM to 5:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:226:20
212.95:236:18
312.95:246:17
412.85:256:15
512.85:266:13
612.75:276:12
712.75:286:10
812.65:306:08
912.65:316:06
1012.65:326:05
1112.55:336:03
1212.55:346:01
1312.45:355:59
1412.45:365:58
1512.35:375:56
1612.35:385:54
1712.25:395:52
1812.25:405:50
1912.15:415:49
2012.15:425:47
2112.05:435:45
2212.05:445:43
2311.95:455:42
2411.95:465:40
2511.85:475:38
2611.85:485:36
2711.85:495:34
2811.75:505:33
2911.75:515:31
3011.65:525:29

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.55 kWh/m².

For context, solar energy here swings from a low near 1.69 kWh/m² to a high of 6.33 kWh/m² in June across the year — September's 4.55 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.0Bright
35.0Bright
45.0Bright
54.9Bright
64.9Bright
74.9Bright
84.8Bright
94.8Bright
104.7Bright
114.7Bright
124.7Bright
134.6Bright
144.6Bright
154.5Bright
164.5Bright
174.5Bright
184.4Bright
194.4Bright
204.3Bright
214.3Bright
224.3Bright
234.2Bright
244.2Bright
254.1Bright
264.1Bright
274.0Bright
284.0Moderate
294.0Moderate
303.9Moderate
Planning a trip in September

Is September a good time to visit Bourbonnais?

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

7.1
Sightseeing
1st-best month of the year
6.0
Beach & pool
4th-best month of the year

September is one of the better times to visit Bourbonnais for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Bourbonnais in September

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

In September, Bourbonnais sees daytime highs around 76°F and nights near 56°F. Worth packing: light clothes, rain gear and sun protection. About 8 days see rain.

light clothesrain gearsun protection

Sea temperature near Bourbonnais 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 42 mi away) is warmest in August at about 73°F and coldest in February near 35°F.

It's comfortable for a long swim from Jul 10 to Sep 16 — about 2.3 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb35Bracing
Mar35Bracing
Apr39Bracing
May46Bracing
Jun59Cool
Jul70Refreshing
Aug73Refreshing
Sep68Refreshing
Oct58Bracing
Nov49Bracing
Dec42Bracing

UV index in Bourbonnais 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 Bourbonnais peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 21UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Bourbonnais 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 Bourbonnais is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1418 µg/m³Oct 238 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar15Moderate
Apr15Moderate
May17Moderate
Jun17Moderate
Jul18Moderate
Aug16Moderate
Sep12Moderate
Oct8Good
Nov9Good
Dec10Good
Location & terrain

Where is Bourbonnais?

Bourbonnais sits at 41.2°N, 87.9°W, 650 ft above sea level, in United States. The nearest listed city is Bradley, 1.9 mi away.

Topography around Bourbonnais

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

Within 2 miles, the terrain around Bourbonnais has only modest variations in elevation — a maximum elevation change of 174 ft around an average of 659 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 272 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 597 ft.

The land around Bourbonnais is covered by artificial surfaces (32%), trees (27%) and grassland (21%) within 2 miles, cropland (75%) within 10 miles, and cropland (68%) within 50 miles.

2 miles
174 ft
10 miles
272 ft
50 miles
597 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Bradley 1.9 mi · Kankakee 2.5 mi · Frankfort 24 mi · New Lenox 25 mi · Mokena 25 mi · Park Forest 26 mi · Matteson 26 mi · Joliet 27 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 Bourbonnais (41.1538°, -87.8875°, elevation 650 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. 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).