Normal weather in September

In September, Normal sees average daytime highs of 76°F and overnight lows near 56°F, with 3.0 in of rain across 7.8 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 81°F in the first days to 72°F by the end. The sky is clear or mostly clear about 45% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Normal's 1st-clearest and 9th-windiest month. For the whole year in context, see Normal's year-round climate.

Daytime high
76°
4th warmest
Overnight low
56°
9th coldest
Rainfall
3.0 in
7.8 wet days
Daylight
12 h 18 min
5:42 AM – 5:58 PM
Cloud cover
47%
1st clearest
Wind
8 mph
9th windiest
Solar energy
4.65 kWh/m²
Travel score
7.2
out of 10

Normal is town in McLean County, Illinois, United States.

Density
1,140/km²
people per km²
Founded
1865

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 81°F in the first days to 72°F by the end.

A typical September day in Normal 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 66°F and 87°F. Set against its neighbours, September runs about 6°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18162
28162
38161
48061
58061
68060
78060
87959
97959
107959
117858
127858
137857
147757
157757
167656
177656
187655
197555
207555
217554
227454
237453
247453
257353
267352
277352
287251
297251
307151

How September really feels in Normal

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.

Normal weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan33° / 19°2.38.34.99.40.0
Feb38° / 22°2.17.44.110.40.0
Mar50° / 32°3.110.31.811.72.2
Apr62° / 43°4.4120.5134.9
May72° / 53°4.713.5014.26.1
Jun81° / 63°4.312.2014.86.1
Jul83° / 66°3.810.8014.65.7
Aug82° / 64°3.29.4013.66.5
Sep76° / 56°3.07.8012.37.2
Oct64° / 45°3.38.90.110.95.8
Nov50° / 34°3.08.41.19.72.3
Dec38° / 24°2.38.33.69.20.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 45% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 41%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16337
26337
36337
46337
56436
66436
76436
86337
96337
106238
116139
126040
135941
145941
155842
165743
175743
185644
195644
205644
215644
225743
235644
245644
255644
265644
275644
285644
295644
305644

Chance of precipitation in September

Any precipitation

Normal gets around 3.0 in of rain over 7.8 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 27% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
128
228
328
428
528
628
728
828
928
1028
1129
1229
1329
1429
1529
1629
1728
1828
1928
2027
2127
2226
2326
2426
2526
2625
2725
2825
2925
3025

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 15% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
12022252410
2212324239
3232324228
4242424217
5262524206
6282523195
7302523185
8322522174
9342522164
10352522153
11372421143
12392421142
13412320132
14432319132
15452219122
16472118121
17502117111
18522017101
19541916101
2056191591
2159181490
2262171380
2362171380
2465161270
2566161170
2668151160
2769151060
2871141050
297214950
307214950

Wind in September

Winds average 8 mph in September.

Across September, daily wind ranges from about 7 mph on the calmest days to 9 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
97light 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
309light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 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 78 minutes over September. Sunrise moves from 5:27 AM to 5:57 AM, and sunset from 6:24 PM to 5:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:276:24
212.95:286:22
312.95:296:21
412.85:306:19
512.85:316:17
612.75:326:16
712.75:336:14
812.65:346:12
912.65:356:10
1012.55:366:09
1112.55:376:07
1212.45:386:05
1312.45:396:03
1412.45:406:02
1512.35:416:00
1612.35:425:58
1712.25:435:56
1812.25:445:55
1912.15:455:53
2012.15:465:51
2112.05:475:49
2212.05:485:48
2311.95:495:46
2411.95:505:44
2511.95:515:43
2611.85:525:41
2711.85:545:39
2811.75:555:37
2911.75:565:36
3011.65:575:34

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.65 kWh/m².

For context, solar energy here swings from a low near 1.77 kWh/m² to a high of 6.4 kWh/m² in July across the year — September's 4.65 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.1Bright
45.1Bright
55.0Bright
65.0Bright
75.0Bright
84.9Bright
94.9Bright
104.8Bright
114.8Bright
124.8Bright
134.7Bright
144.7Bright
154.6Bright
164.6Bright
174.5Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.3Bright
234.3Bright
244.3Bright
254.2Bright
264.2Bright
274.1Bright
284.1Bright
294.1Bright
304.0Bright
Planning a trip in September

Is September a good time to visit Normal?

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
6.3
Beach & pool
3rd-best month of the year

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

What to pack for Normal in September

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

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

light clothessun protection

UV index in Normal 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 Normal peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 highHighModerateJun 22UV 9Dec 23UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Normal 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 Normal is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodJul 1816 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar13Moderate
Apr11Good
May14Moderate
Jun14Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Normal?

Normal sits at 40.5°N, 89.0°W, 801 ft above sea level, in United States. The nearest listed city is Bloomington, 1.9 mi away.

Topography around Normal

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

Within 2 miles, the terrain around Normal has only modest variations in elevation — a maximum elevation change of 151 ft around an average of 810 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 276 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 531 ft.

The land around Normal is covered by artificial surfaces (39%), trees (30%) and grassland (21%) within 2 miles, cropland (74%) within 10 miles, and cropland (83%) within 50 miles.

2 miles
151 ft
10 miles
276 ft
50 miles
531 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Bloomington 1.9 mi · Washington 25 mi · Morton 25 mi · East Peoria 33 mi · Peoria 34 mi · North Peoria 34 mi · Pekin 34 mi · Decatur 47 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 Normal (40.5142°, -88.9906°, elevation 801 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. 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).