Sycamore weather in August

In August, Sycamore sees average daytime highs of 80°F and overnight lows near 62°F, with 3.5 in of rain across 10.4 wet days and about 13.7 hours of daylight. It is the 2nd-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 80°F through the month. The sky is clear or mostly clear about 36% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 14 h 18 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Sycamore's 2nd-clearest and 12th-windiest month. For the whole year in context, see Sycamore's year-round climate.

Daytime high
80°
2nd warmest
Overnight low
62°
11th coldest
Rainfall
3.5 in
10.4 wet days
Daylight
13 h 42 min
5:08 AM – 6:50 PM
Cloud cover
54%
2nd clearest
Wind
6 mph
12th windiest
Solar energy
5.42 kWh/m²
Travel score
6.6
out of 10

Sycamore is city in Illinois, United States.

Density
700/km²
people per km²
Founded
1835

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 80°F through the month.

A typical August day in Sycamore reaches about 80°F in the afternoon and slips back to 62°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 73°F and 87°F. Set against its neighbours, August runs about 2°F cooler than July and about 6°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18164
28164
38164
48163
58163
68163
78063
88063
98063
108063
118063
128062
138062
148062
158062
168062
178062
188062
198062
208062
218062
228062
238062
248062
257962
267961
277961
287961
297961
307960
317960

How August really feels in Sycamore

Once humidity and wind are folded in, August 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

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Sycamore weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan29° / 16°2.07.65.79.30.0
Feb34° / 19°1.86.94.910.30.0
Mar46° / 29°2.69.32.911.71.3
Apr59° / 40°4.4120.913.14.1
May69° / 50°4.812.8014.35.9
Jun78° / 60°4.212.20156.3
Jul82° / 64°3.510.7014.76.4
Aug80° / 62°3.510.4013.76.6
Sep74° / 54°3.28.7012.37.0
Oct61° / 43°3.19.10.110.95.2
Nov47° / 32°2.47.71.69.61.5
Dec35° / 22°2.27.84.590.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 20% of August, with mostly cloudy or overcast conditions the remaining 44%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35842
45842
55842
65743
75644
85644
95644
105644
115644
125644
135545
145545
155545
165545
175644
185644
195545
205545
215545
225446
235545
245545
255545
265644
275743
285842
295842
305842
315842

Chance of precipitation in August

Any precipitation

Sycamore gets around 3.5 in of rain over 10.4 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 33% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
134
234
334
434
533
633
733
833
933
1033
1133
1233
1333
1433
1534
1634
1734
1834
1934
2034
2134
2234
2334
2433
2533
2632
2732
2831
2931
3030
3130

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels comfortable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the comfortable band about 25% of days. Sticky, muggy-or-worse air turns up on roughly 34% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
112252525121
212262525121
312262525121
412262524121
512262524121
613262523120
713262523120
814262523120
914262523120
1014262522120
1115262522120
1215262522120
1315262522120
1415262522110
1516252523110
1616252523110
1716252523110
1816242524110
1916242524100
2016242525100
2116242525100
2216242525100
2316242525100
2417252425100
251725242590
261825242490
271926232490
282026232390
292126222280
302227222280
312327212180

Wind in August

Winds average 6 mph in August, the calmest month.

Across August, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 18 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over August. Sunrise moves from 4:52 AM to 5:24 AM, and sunset from 7:10 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.34:527:10
214.34:537:09
314.24:547:07
414.24:557:06
514.24:567:05
614.14:577:04
714.14:587:03
814.04:597:01
914.05:007:00
1014.05:016:59
1113.95:026:57
1213.95:036:56
1313.85:046:55
1413.85:056:53
1513.85:066:52
1613.75:086:50
1713.75:096:49
1813.65:106:47
1913.65:116:46
2013.55:126:44
2113.55:136:43
2213.45:146:41
2313.45:156:39
2413.45:166:38
2513.35:176:36
2613.35:186:34
2713.25:196:33
2813.25:206:31
2913.15:216:29
3013.15:236:28
3113.05:246:26

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.42 kWh/m².

For context, solar energy here swings from a low near 1.69 kWh/m² to a high of 6.29 kWh/m² in June across the year — August's 5.42 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.8Bright
45.8Bright
55.8Bright
65.7Bright
75.7Bright
85.7Bright
95.6Bright
105.6Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.4Bright
165.4Bright
175.4Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.2Bright
235.2Bright
245.2Bright
255.2Bright
265.1Bright
275.1Bright
285.1Bright
295.1Bright
305.0Bright
315.0Bright
Planning a trip in August

Is August a good time to visit Sycamore?

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

6.6
Sightseeing
2nd-best month of the year
6.6
Beach & pool
2nd-best month of the year

August is a reasonable time to visit Sycamore for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Sycamore in August

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

In August, Sycamore sees daytime highs around 80°F and nights near 62°F. Worth packing: light clothes, rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in Sycamore in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sycamore peaks around June 19 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 19UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Sycamore in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.

Air quality in Sycamore 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 Sycamore?

Sycamore sits at 42.0°N, 88.7°W, 873 ft above sea level, in United States. The nearest listed city is DeKalb, 5.0 mi away.

Topography around Sycamore

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

Within 2 miles, the terrain around Sycamore has only modest variations in elevation — a maximum elevation change of 115 ft around an average of 853 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 328 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 846 ft.

The land around Sycamore is covered by cropland (38%), grassland (22%) and artificial surfaces (21%) within 2 miles, cropland (79%) within 10 miles, and cropland (56%) and trees (20%) within 50 miles.

2 miles
115 ft
10 miles
328 ft
50 miles
846 ft
treesgrasslandcroplandartificial surfaceswater
August weather nearby: DeKalb 5.0 mi · Wasco 15 mi · Huntley 18 mi · St. Charles 20 mi · South Elgin 21 mi · Belvidere 21 mi · Geneva 21 mi · Elgin 21 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 Sycamore (41.9889°, -88.6868°, elevation 873 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).