Lake in the Hills weather in September

In September, Lake in the Hills sees average daytime highs of 73°F and overnight lows near 55°F, with 3.0 in of rain across 8.8 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 78°F in the first days to 68°F by the end. The sky is clear or mostly clear about 41% 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 Lake in the Hills's 1st-clearest and 9th-windiest month. For the whole year in context, see Lake in the Hills's year-round climate.

Daytime high
73°
4th warmest
Overnight low
55°
9th coldest
Rainfall
3.0 in
8.8 wet days
Daylight
12 h 18 min
5:39 AM – 5:56 PM
Cloud cover
51%
1st clearest
Wind
7 mph
9th windiest
Solar energy
4.38 kWh/m²
Travel score
7.0
out of 10

Lake in the Hills is village in Illinois, United States.

Density
1,056/km²
people per km²
Founded
1952

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 78°F in the first days to 68°F by the end.

A typical September day in Lake in the Hills reaches about 73°F in the afternoon and slips back to 55°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 83°F. Set against its neighbours, September runs about 7°F cooler than August and about 13°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17861
27861
37860
47760
57760
67759
77659
87658
97658
107558
117557
127457
137456
147456
157356
167355
177355
187255
197254
207154
217153
227153
237052
247052
256952
266951
276951
286850
296850
306749

How September really feels in Lake in the Hills

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.

Lake in the Hills 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
Jan30° / 17°2.07.969.30.0
Feb34° / 20°1.975.210.30.0
Mar45° / 29°2.59.73.311.61.1
Apr57° / 39°4.312.31.113.13.7
May68° / 50°4.312.2014.45.9
Jun78° / 61°3.811.80156.4
Jul82° / 65°3.410.4014.86.4
Aug80° / 63°3.610.6013.76.6
Sep73° / 55°3.08.8012.37.0
Oct60° / 44°3.08.70.210.85.0
Nov46° / 33°2.47.81.69.61.4
Dec35° / 22°2.184.690.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15842
25941
36040
46040
56040
66139
76139
86139
96040
106040
116040
125842
135842
145743
155743
165644
175644
185545
195545
205446
215446
225446
235347
245347
255347
265149
275149
285248
295248
305347

Chance of precipitation in September

Any precipitation

Lake in the Hills gets around 3.0 in of rain over 8.8 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 30% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
128
228
328
428
528
629
729
829
929
1030
1130
1231
1331
1431
1532
1632
1732
1832
1931
2031
2131
2231
2331
2431
2531
2630
2730
2830
2929
3029

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 51% of days. Sticky, muggy-or-worse air turns up on roughly 12% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1222922216
2242921206
3263021195
4283020175
5302920164
6322920154
7342919154
8362819143
9382719133
10392619133
11422618122
12442518112
13462418112
14482317101
15492317101
1651221791
1753211691
1855201681
1958201570
2060191470
2163181360
2265171260
2366171250
2468161150
2570161040
267215940
277215940
287514830
297613830
307713730

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.

0246810151015202530
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227light 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 5:23 AM to 5:55 AM, and sunset from 6:23 PM to 5:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:236:23
213.05:246:21
312.95:256:20
412.95:266:18
512.85:276:16
612.85:286:14
712.75:306:12
812.75:316:11
912.65:326:09
1012.65:336:07
1112.55:346:05
1212.55:356:03
1312.45:366:02
1412.45:376:00
1512.35:385:58
1612.35:395:56
1712.25:405:54
1812.25:415:52
1912.15:435:51
2012.15:445:49
2112.05:455:47
2212.05:465:45
2311.95:475:43
2411.95:485:41
2511.85:495:40
2611.85:505:38
2711.75:515:36
2811.75:525:34
2911.65:545:32
3011.65:555:31

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.38 kWh/m².

For context, solar energy here swings from a low near 1.6 kWh/m² to a high of 6.32 kWh/m² in June across the year — September's 4.38 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.8Bright
54.8Bright
64.8Bright
74.7Bright
84.7Bright
94.6Bright
104.6Bright
114.5Bright
124.5Bright
134.5Bright
144.4Bright
154.4Bright
164.3Bright
174.3Bright
184.3Bright
194.2Bright
204.2Bright
214.1Bright
224.1Bright
234.0Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.8Moderate
293.8Moderate
303.8Moderate
Planning a trip in September

Is September a good time to visit Lake in the Hills?

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

7.0
Sightseeing
1st-best month of the year
5.2
Beach & pool
4th-best month of the year

September is one of the better times to visit Lake in the Hills for general sightseeing.

What to pack for Lake in the Hills in September

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

In September, Lake in the Hills sees daytime highs around 73°F and nights near 55°F. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Lake in the Hills in September

The nearest coast averages about 67°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 27 mi away) is warmest in August at about 71°F and coldest in March near 36°F.

It's comfortable for a long swim from Jul 18 to Sep 8 — about 1.7 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr38Bracing
May43Bracing
Jun55Bracing
Jul68Refreshing
Aug71Refreshing
Sep67Cool
Oct57Bracing
Nov47Bracing
Dec42Bracing

UV index in Lake in the Hills 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 Lake in the Hills peaks around June 20 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 20UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Lake in the Hills 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 Lake in the Hills is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJul 1817 µg/m³Oct 229 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar16Moderate
Apr14Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug16Moderate
Sep13Moderate
Oct9Good
Nov10Good
Dec11Good
Location & terrain

Where is Lake in the Hills?

Lake in the Hills sits at 42.2°N, 88.3°W, 866 ft above sea level, in United States. The nearest listed city is Algonquin, 1.9 mi away.

Topography around Lake in the Hills

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

Within 2 miles, the terrain around Lake in the Hills has only modest variations in elevation — a maximum elevation change of 190 ft around an average of 869 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 377 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 787 ft.

The land around Lake in the Hills is covered by trees (34%), grassland (32%) and artificial surfaces (28%) within 2 miles, trees (38%), grassland (26%) and cropland (20%) within 10 miles, and cropland (40%) and trees (21%) within 50 miles.

2 miles
190 ft
10 miles
377 ft
50 miles
787 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Algonquin 1.9 mi · Crystal Lake 4.3 mi · Huntley 5.0 mi · Cary 5.0 mi · Carpentersville 5.6 mi · Elgin 11 mi · McHenry 11 mi · Woodstock 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 Lake in the Hills (42.1817°, -88.3304°, elevation 866 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).