Marion weather in July

In July, Marion sees average daytime highs of 88°F and overnight lows near 72°F, with 3.5 in of rain across 10.2 wet days and about 14.3 hours of daylight. It is the 1st-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 88°F through the month. The sky is clear or mostly clear about 37% of the time in July, and the air most often feels oppressive.

Daylight stretches from about 14 h 36 min at the start of July to 14 hours by month's end. Set against the rest of the year, July is Marion's 4th-clearest and 11th-windiest month. For the whole year in context, see Marion's year-round climate.

Daytime high
88°
1st warmest
Overnight low
72°
12th coldest
Rainfall
3.5 in
10.2 wet days
Daylight
14 h 24 min
4:50 AM – 7:13 PM
Cloud cover
53%
4th clearest
Wind
5 mph
11th windiest
Solar energy
6.36 kWh/m²
Travel score
4.5
out of 10

Marion is city in and the county seat of Williamson County, Illinois, United States.

Density
412/km²
people per km²
Founded
1839

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 88°F through the month.

A typical July day in Marion reaches about 88°F in the afternoon and slips back to 72°F overnight — a 16°F spread between the day's warmth and the night's chill. On most days the high lands between 81°F and 94°F. Set against its neighbours, July runs about 3°F warmer than June and on par with August.

60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18771
28771
38771
48871
58871
68871
78872
88872
98872
108872
118872
128872
138872
148872
158872
168872
178872
188872
198872
208872
218872
228872
238872
248872
258872
268871
278871
288871
298871
308871
318871

How July really feels in Marion

Once humidity and wind are folded in, July averages 31 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
31
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.

Marion 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
Jan42° / 28°3.492.39.70.3
Feb47° / 31°3.18.12.310.51.5
Mar57° / 39°4.211.40.911.74.0
Apr68° / 49°5.011.4012.96.0
May76° / 60°4.612.60146.3
Jun85° / 68°3.610.6014.65.2
Jul88° / 72°3.510.2014.34.5
Aug87° / 69°2.88.1013.55.1
Sep81° / 61°2.97.5012.36.9
Oct69° / 50°3.57.60116.9
Nov56° / 39°3.88.70.5103.9
Dec46° / 31°3.38.91.89.41.2

Cloud cover in July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% of the time in July.

Beyond those clear spells, partly cloudy skies cover about 20% of July, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25644
35644
45644
55644
65644
75644
85644
95644
105644
115644
125545
135545
145545
155446
165446
175446
185545
195545
205545
215644
225644
235743
245743
255842
265941
275941
285941
296040
306040
316139

Chance of precipitation in July

Any precipitation

Marion gets around 3.5 in of rain over 10.2 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 32% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
236
335
435
535
634
734
834
934
1033
1133
1232
1332
1432
1532
1632
1732
1832
1931
2031
2131
2231
2331
2431
2530
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 41% of days. Sticky, muggy-or-worse air turns up on roughly 72% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
15101933321
24101933331
3491932341
4491932351
5391931362
6391931372
7391930382
8291830392
9281830402
10281729412
11281729432
12181628442
13181628453
14181627453
15181526463
16181526474
17181525474
18191525474
19191424474
201101424474
211101524464
221101524464
231101524454
241111624444
251111724434
261111725424
271111825413
281111926403
291111927383
302112027383
312112028372

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
125calm
135calm
145calm
155calm
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 36 min at the start of July to 14 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 36 minutes over July. Sunrise moves from 4:42 AM to 5:02 AM, and sunset from 7:16 PM to 7:02 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.64:427:16
214.64:427:16
314.64:437:16
414.64:437:16
514.54:437:16
614.54:447:16
714.54:457:16
814.54:457:15
914.54:467:15
1014.54:467:15
1114.54:477:15
1214.44:487:14
1314.44:487:14
1414.44:497:13
1514.44:497:13
1614.44:507:13
1714.44:517:12
1814.34:527:11
1914.34:527:11
2014.34:537:10
2114.34:547:10
2214.24:557:09
2314.24:557:08
2414.24:567:08
2514.24:577:07
2614.14:587:06
2714.14:597:05
2814.14:597:04
2914.15:007:04
3014.05:017:03
3114.05:027:02

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 6.36 kWh/m².

For context, solar energy here swings from a low near 1.93 kWh/m² to a high of 6.45 kWh/m² in June across the year — July's 6.36 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.5Intense
26.5Intense
36.5Intense
46.5Intense
56.5Intense
66.5Intense
76.5Intense
86.5Intense
96.5Intense
106.5Intense
116.4Intense
126.4Intense
136.4Intense
146.4Intense
156.4Intense
166.4Intense
176.4Intense
186.4Intense
196.4Intense
206.4Intense
216.3Intense
226.3Intense
236.3Intense
246.3Intense
256.3Intense
266.3Intense
276.2Intense
286.2Intense
296.2Intense
306.2Intense
316.2Intense
Planning a trip in July

Is July a good time to visit Marion?

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

4.5
Sightseeing
7th-best month of the year
6.7
Beach & pool
4th-best month of the year

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

What to pack for Marion in July

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

In July, Marion sees daytime highs around 88°F and nights near 72°F. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

light clothessun protectionrain gear

UV index in Marion 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 Marion peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 23UV 9Dec 22UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Moderate

Air quality in Marion 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 Marion is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (November, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1318 µg/m³Nov 128 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb11Good
Mar12Moderate
Apr11Good
May14Moderate
Jun17Moderate
Jul19Moderate
Aug14Moderate
Sep12Good
Oct8Good
Nov8Good
Dec8Good
Location & terrain

Where is Marion?

Marion sits at 37.7°N, 88.9°W, 423 ft above sea level, in United States. The nearest listed city is Carbondale, 16 mi away.

Topography around Marion

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

Within 2 miles, the terrain around Marion has only modest variations in elevation — a maximum elevation change of 148 ft around an average of 446 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 331 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,030 ft.

The land around Marion is covered by trees (32%), grassland (26%) and artificial surfaces (24%) within 2 miles, trees (51%), grassland (21%) and cropland (20%) within 10 miles, and trees (46%) and cropland (40%) within 50 miles.

2 miles
148 ft
10 miles
331 ft
50 miles
1,030 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
July weather nearby: Carbondale 16 mi · Mount Vernon 40 mi · Cape Girardeau 43 mi · Paducah 48 mi · Sikeston 69 mi · Henderson 74 mi · Evansville 77 mi · Belleville 79 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 Marion (37.7306°, -88.9331°, elevation 423 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).