Galesburg weather in August

In August, Galesburg sees average daytime highs of 82°F and overnight lows near 64°F, with 3.3 in of rain across 9.4 wet days and about 13.6 hours of daylight. It is the 2nd-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 82°F through the month. The sky is clear or mostly clear about 41% of the time in August, and the air most often feels humid.

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

Daytime high
82°
2nd warmest
Overnight low
64°
11th coldest
Rainfall
3.3 in
9.4 wet days
Daylight
13 h 36 min
5:16 AM – 6:55 PM
Cloud cover
51%
2nd clearest
Wind
6 mph
12th windiest
Solar energy
5.64 kWh/m²
Travel score
6.5
out of 10

Galesburg is county seat of Knox County, Illinois, United States.

Density
674/km²
people per km²
Founded
1837

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 82°F through the month.

A typical August day in Galesburg reaches about 82°F in the afternoon and slips back to 64°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 74°F and 89°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)
18365
28365
38365
48365
58365
68265
78265
88265
98265
108264
118264
128264
138264
148264
158264
168264
178264
188264
198264
208264
218264
228264
238263
248263
258263
268163
278163
288163
298162
308162
318162

How August really feels in Galesburg

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.

Galesburg weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan32° / 17°2.07.85.29.40.0
Feb36° / 21°2.07.14.310.40.0
Mar49° / 31°2.910.12.211.71.9
Apr61° / 42°4.4120.713.14.7
May71° / 53°4.713.2014.36.1
Jun80° / 63°4.711.6014.96.2
Jul83° / 66°3.59.6014.65.8
Aug82° / 64°3.39.4013.66.5
Sep76° / 56°3.48.5012.37.2
Oct63° / 44°2.98.70.210.95.7
Nov48° / 33°2.67.71.29.72.0
Dec37° / 23°2.17.13.69.10.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 40%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16040
26040
36040
46040
55941
65941
75941
85941
95941
105941
115941
125941
136040
146040
155941
165941
175941
185941
195941
206040
216040
226040
235941
245941
255941
266040
276040
286139
296139
306139
316238

Chance of precipitation in August

Any precipitation

Galesburg gets around 3.3 in of rain over 9.4 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 30% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
130
230
329
429
529
629
729
829
929
1030
1130
1230
1331
1431
1531
1631
1731
1832
1932
2032
2132
2232
2332
2431
2531
2630
2730
2830
2929
3029
3129

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the humid band about 26% of days. Sticky, muggy-or-worse air turns up on roughly 42% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
19192626201
29192626201
39192626191
49192625191
510192725181
610192725181
710192725181
811192724171
911192824171
1012192824171
1112192824161
1212192824161
1312202724161
1412202724161
1512202724151
1613202725151
1713202725151
1813202626151
1913192626151
2013192627151
2112192527151
2212202528151
2313202528150
2413202428140
2513212428140
2614212328140
2715222327130
2816222327130
2917222326120
3018232326110
3119232325100

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
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 12 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 72 minutes over August. Sunrise moves from 5:01 AM to 5:31 AM, and sunset from 7:14 PM to 6:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.25:017:14
214.25:027:13
314.15:037:12
414.15:047:11
514.15:057:09
614.05:067:08
714.05:077:07
814.05:087:06
913.95:097:05
1013.95:107:03
1113.85:117:02
1213.85:127:01
1313.85:136:59
1413.75:146:58
1513.75:156:56
1613.65:166:55
1713.65:176:54
1813.65:186:52
1913.55:196:51
2013.55:206:49
2113.45:216:48
2213.45:226:46
2313.45:236:45
2413.35:246:43
2513.35:256:41
2613.25:266:40
2713.25:276:38
2813.15:286:37
2913.15:296:35
3013.05:306:33
3113.05:316:32

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.64 kWh/m².

For context, solar energy here swings from a low near 1.75 kWh/m² to a high of 6.41 kWh/m² in June across the year — August's 5.64 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.1Intense
46.0Intense
56.0Intense
66.0Bright
75.9Bright
85.9Bright
95.9Bright
105.8Bright
115.8Bright
125.8Bright
135.7Bright
145.7Bright
155.7Bright
165.6Bright
175.6Bright
185.6Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.4Bright
245.4Bright
255.4Bright
265.3Bright
275.3Bright
285.3Bright
295.3Bright
305.2Bright
315.2Bright
Planning a trip in August

Is August a good time to visit Galesburg?

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

6.5
Sightseeing
2nd-best month of the year
7.0
Beach & pool
2nd-best month of the year

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

What to pack for Galesburg in August

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

In August, Galesburg sees daytime highs around 82°F and nights near 64°F. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Galesburg 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 Galesburg peaks around June 19 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 highHighModerateJun 19UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Galesburg 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 Galesburg 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 1915 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar13Moderate
Apr11Good
May13Moderate
Jun13Moderate
Jul16Moderate
Aug15Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Galesburg?

Galesburg sits at 40.9°N, 90.4°W, 771 ft above sea level, in United States. The nearest listed city is Macomb, 37 mi away.

Topography around Galesburg

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

Within 2 miles, the terrain around Galesburg has only modest variations in elevation — a maximum elevation change of 75 ft around an average of 778 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 259 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 528 ft.

The land around Galesburg is covered by artificial surfaces (31%), trees (26%) and grassland (22%) within 2 miles, cropland (67%) and trees (21%) within 10 miles, and cropland (68%) and trees (21%) within 50 miles.

2 miles
75 ft
10 miles
259 ft
50 miles
528 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Macomb 37 mi · East Moline 39 mi · Moline 39 mi · Burlington 40 mi · Rock Island 40 mi · Bettendorf 40 mi · Davenport 41 mi · North Peoria 44 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 Galesburg (40.9478°, -90.3712°, elevation 771 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).