Upper Alton weather in August

In August, Upper Alton sees average daytime highs of 85°F and overnight lows near 67°F, with 2.9 in of rain across 8.9 wet days and about 13.5 hours of daylight. It is the 2nd-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 85°F through the month. The sky is clear or mostly clear about 43% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 h 06 min at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Upper Alton's 2nd-clearest and 12th-windiest month. For the whole year in context, see Upper Alton's year-round climate.

Daytime high
85°
2nd warmest
Overnight low
67°
11th coldest
Rainfall
2.9 in
8.9 wet days
Daylight
13 h 30 min
5:19 AM – 6:51 PM
Cloud cover
50%
2nd clearest
Wind
5 mph
12th windiest
Solar energy
5.78 kWh/m²
Travel score
5.5
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 85°F through the month.

A typical August day in Upper Alton reaches about 85°F in the afternoon and slips back to 67°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 78°F and 93°F. Set against its neighbours, August runs about 1°F cooler than July and about 6°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18669
28669
38669
48669
58669
68669
78668
88668
98568
108568
118568
128568
138568
148568
158568
168567
178567
188567
198567
208567
218567
228567
238567
248567
258567
268567
278566
288566
298466
308466
318465

How August really feels in Upper Alton

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.

Upper Alton weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 24°2.68.23.29.60.0
Feb43° / 27°2.47.6310.50.6
Mar54° / 36°3.610.41.511.73.3
Apr66° / 47°4.611.60.2135.7
May75° / 58°5.013.5014.16.2
Jun83° / 67°4.010.9014.75.6
Jul87° / 70°3.29.5014.45.0
Aug85° / 67°2.98.9013.55.5
Sep79° / 59°3.37.5012.37.2
Oct67° / 48°3.38.40.1116.5
Nov53° / 37°3.68.60.79.93.2
Dec42° / 28°2.48.12.39.30.4

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% 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 38%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15941
26040
36040
46040
56040
66040
76139
86238
96238
106238
116337
126337
136337
146436
156436
166337
176337
186337
196337
206337
216337
226337
236337
246238
256238
266238
276238
286337
296337
306337
316436

Chance of precipitation in August

Any precipitation

Upper Alton gets around 2.9 in of rain over 8.9 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 29% and peaks near 30% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
130
230
330
430
530
630
730
830
930
1030
1130
1230
1330
1430
1529
1629
1729
1829
1929
2029
2129
2228
2328
2428
2527
2627
2726
2826
2925
3025
3125

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the muggy band about 33% of days. Sticky, muggy-or-worse air turns up on roughly 57% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
13132230301
23132231291
33132232291
44132232281
54132233271
64132233271
74132234261
85142134251
95142134251
105142134251
115152034241
126152034241
136162034241
146162034231
156162133231
166162133231
176162133231
186162133231
196162132231
206162232231
216162232231
226162232241
236152232241
246152232231
257152232230
267152232230
277152233220
288162232210
299162232210
3010162232200
3111172231190

Wind in August

Winds average 5 mph in August, the calmest month.

Across August, 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
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 06 min at the start of August to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over August. Sunrise moves from 5:05 AM to 5:33 AM, and sunset from 7:08 PM to 6:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.15:057:08
214.05:067:07
314.05:077:06
414.05:087:05
513.95:097:04
613.95:107:03
713.95:107:02
813.85:117:01
913.85:127:00
1013.85:136:58
1113.75:146:57
1213.75:156:56
1313.65:166:55
1413.65:176:53
1513.65:186:52
1613.55:196:51
1713.55:206:49
1813.55:216:48
1913.45:226:47
2013.45:226:45
2113.35:236:44
2213.35:246:42
2313.35:256:41
2413.25:266:39
2513.25:276:38
2613.15:286:36
2713.15:296:35
2813.15:306:33
2913.05:316:32
3013.05:326:30
3112.95:336:29

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.78 kWh/m².

For context, solar energy here swings from a low near 1.88 kWh/m² to a high of 6.44 kWh/m² in June across the year — August's 5.78 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.2Intense
26.2Intense
36.1Intense
46.1Intense
56.1Intense
66.0Intense
76.0Intense
86.0Intense
96.0Bright
105.9Bright
115.9Bright
125.9Bright
135.8Bright
145.8Bright
155.8Bright
165.8Bright
175.7Bright
185.7Bright
195.7Bright
205.7Bright
215.6Bright
225.6Bright
235.6Bright
245.5Bright
255.5Bright
265.5Bright
275.4Bright
285.4Bright
295.4Bright
305.3Bright
315.3Bright
Planning a trip in August

Is August a good time to visit Upper Alton?

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

5.5
Sightseeing
6th-best month of the year
7.3
Beach & pool
1st-best month of the year

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

What to pack for Upper Alton in August

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

In August, Upper Alton sees daytime highs around 85°F and nights near 67°F. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Upper Alton in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Upper Alton 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 Upper Alton 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 Upper Alton 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 Upper Alton?

Upper Alton sits at 38.9°N, 90.2°W, 545 ft above sea level, in United States. The nearest listed city is Alton, 2.5 mi away.

Topography around Upper Alton

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

Within 2 miles, the terrain around Upper Alton has only modest variations in elevation — a maximum elevation change of 249 ft around an average of 518 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 620 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 751 ft.

The land around Upper Alton is covered by trees (55%) and artificial surfaces (22%) within 2 miles, trees (41%) and cropland (32%) within 10 miles, and cropland (49%) and trees (37%) within 50 miles.

2 miles
249 ft
10 miles
620 ft
50 miles
751 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Alton 2.5 mi · Godfrey 3.7 mi · Old Jamestown 8.7 mi · Spanish Lake 9.3 mi · Florissant 12 mi · Edwardsville 12 mi · Ferguson 14 mi · Granite City 14 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 Upper Alton (38.9114°, -90.1507°, elevation 545 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).