Collinsville weather in July

In July, Collinsville sees average daytime highs of 87°F and overnight lows near 70°F, with 3.3 in of rain across 9.6 wet days and about 14.4 hours of daylight. It is the 1st-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 87°F through the month. The sky is clear or mostly clear about 38% of the time in July, and the air most often feels oppressive.

Daylight stretches from about 14 h 42 min at the start of July to 14 h 06 min by month's end. Set against the rest of the year, July is Collinsville's 4th-clearest and 11th-windiest month. For the whole year in context, see Collinsville's year-round climate.

Daytime high
87°
1st warmest
Overnight low
70°
12th coldest
Rainfall
3.3 in
9.6 wet days
Daylight
14 h 30 min
4:52 AM – 7:19 PM
Cloud cover
53%
4th clearest
Wind
5 mph
11th windiest
Solar energy
6.42 kWh/m²
Travel score
4.7
out of 10

Collinsville is city in Illinois, United States.

Density
643/km²
people per km²

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

Temperature in July

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 87°F through the month.

A typical July day in Collinsville reaches about 87°F in the afternoon and slips back to 70°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 80°F and 95°F. Set against its neighbours, July runs about 3°F warmer than June and about 1°F warmer than August.

60°70°80°90°100°151015202531
Avg high (°F)Avg low (°F)
18770
28770
38770
48770
58770
68770
78770
88770
98771
108871
118871
128871
138871
148871
158871
168871
178871
188871
198871
208871
218871
228871
238771
248770
258770
268770
278770
288770
298770
308770
318769

How July really feels in Collinsville

Once humidity and wind are folded in, July averages 24 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
24
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in July is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Collinsville weather by month

How July compares with the rest of the year at a glance. July is the 1st-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 24°2.98.32.99.60.0
Feb44° / 28°2.57.62.710.50.8
Mar55° / 37°3.710.61.411.73.5
Apr67° / 47°4.811.70.1135.8
May76° / 58°5.213.5014.16.2
Jun84° / 67°4.210.8014.65.3
Jul87° / 70°3.39.6014.44.7
Aug86° / 68°3.08.7013.55.3
Sep80° / 60°3.27.7012.37.0
Oct67° / 48°3.58.30116.6
Nov54° / 38°3.78.70.79.93.4
Dec43° / 29°2.68.42.39.30.6

Cloud cover in July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in July.

Beyond those clear spells, partly cloudy skies cover about 19% of July, with mostly cloudy or overcast conditions the remaining 43%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35644
45644
55644
65743
75842
85842
95842
105842
115842
125842
135842
145842
155842
165842
175842
185743
195743
205743
215743
225743
235743
245743
255743
265743
275743
285842
295842
305842
315842

Chance of precipitation in July

Any precipitation

Collinsville gets around 3.3 in of rain over 9.6 wet days in July. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 31% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
235
335
434
534
634
733
832
932
1031
1131
1230
1330
1429
1529
1629
1729
1828
1928
2029
2129
2229
2329
2429
2529
2630
2730
2830
2930
3030
3130

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, July lands in the oppressive band about 36% of days. Sticky, muggy-or-worse air turns up on roughly 65% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
15142133270
25132132280
35132132290
44132132300
54122131311
64122131321
74112131321
83112131331
93102131341
103102131351
11392130361
12392130371
13392030371
14292029382
15292029392
16292028392
17292027402
182101927402
192101926402
202111926402
212111925402
222121925402
232121925402
242131925392
252132025382
262142025372
272142126362
282142126352
292142127341
303142128331
313142129321

Wind in July

Winds average 5 mph in July.

Across July, daily wind ranges from about 5 mph on the calmest days to 6 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
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in July

DaylightNight

Daylight runs from about 14 h 42 min at the start of July to 14 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 36 minutes over July. Sunrise moves from 4:43 AM to 5:04 AM, and sunset from 7:23 PM to 7:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.74:437:23
214.74:447:23
314.74:447:23
414.64:447:23
514.64:457:23
614.64:467:23
714.64:467:23
814.64:477:22
914.64:477:22
1014.64:487:22
1114.54:487:21
1214.54:497:21
1314.54:507:21
1414.54:507:20
1514.54:517:20
1614.54:527:19
1714.44:537:19
1814.44:537:18
1914.44:547:18
2014.44:557:17
2114.34:567:16
2214.34:567:16
2314.34:577:15
2414.34:587:14
2514.24:597:13
2614.25:007:13
2714.25:017:12
2814.25:017:11
2914.15:027:10
3014.15:037:09
3114.15:047:08

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 6.42 kWh/m².

For context, solar energy here swings from a low near 1.88 kWh/m² to a high of 6.46 kWh/m² in June across the year — July's 6.42 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.6Intense
26.6Intense
36.6Intense
46.6Intense
56.6Intense
66.6Intense
76.6Intense
86.6Intense
96.5Intense
106.5Intense
116.5Intense
126.5Intense
136.5Intense
146.5Intense
156.5Intense
166.5Intense
176.5Intense
186.5Intense
196.4Intense
206.4Intense
216.4Intense
226.4Intense
236.3Intense
246.3Intense
256.3Intense
266.3Intense
276.3Intense
286.3Intense
296.2Intense
306.2Intense
316.2Intense
Planning a trip in July

Is July a good time to visit Collinsville?

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

4.7
Sightseeing
7th-best month of the year
6.8
Beach & pool
3rd-best month of the year

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

What to pack for Collinsville in July

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

In July, Collinsville sees daytime highs around 87°F and nights near 70°F. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

light clothessun protectionrain gear

UV index in Collinsville in July

LowModerateHighVery highExtreme

Clear-sky midday UV in July peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Collinsville peaks around June 21 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 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 21UV 9Dec 23UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Collinsville in July

GoodModeratePoorUnhealthyVery unhealthy

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

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

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodAug 1018 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar13Moderate
Apr11Good
May14Moderate
Jun16Moderate
Jul18Moderate
Aug18Moderate
Sep13Moderate
Oct8Good
Nov9Good
Dec10Good
Location & terrain

Where is Collinsville?

Collinsville sits at 38.7°N, 90.0°W, 561 ft above sea level, in United States. The nearest listed city is Fairview Heights, 5.6 mi away.

Topography around Collinsville

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

Within 2 miles, the terrain around Collinsville has only modest variations in elevation — a maximum elevation change of 190 ft around an average of 531 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 299 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 866 ft.

The land around Collinsville is covered by trees (66%) within 2 miles, trees (40%) and cropland (28%) within 10 miles, and cropland (49%) and trees (38%) within 50 miles.

2 miles
190 ft
10 miles
299 ft
50 miles
866 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
July weather nearby: Fairview Heights 5.6 mi · O'Fallon 6.8 mi · Granite City 9.3 mi · East Saint Louis 9.3 mi · Edwardsville 9.9 mi · Belleville 11 mi · St. Louis 12 mi · Spanish Lake 15 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 Collinsville (38.6703°, -89.9845°, elevation 561 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).