Alton weather in October

In October, Alton sees average daytime highs of 67°F and overnight lows near 48°F, with 3.3 in of precipitation across 8.4 wet days and about 11 hours of daylight. It is the 6th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 73°F in the first days to 61°F by the end. The sky is clear or mostly clear about 44% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 36 min at the start of October to 10 h 24 min by month's end. Set against the rest of the year, October is Alton's 3rd-clearest and 7th-windiest month. For the whole year in context, see Alton's year-round climate.

Daytime high
67°
6th warmest
Overnight low
48°
7th coldest
Precipitation
3.3 in
8.4 wet days
Daylight
11 hours
6:17 AM – 5:15 PM
Cloud cover
51%
3rd clearest
Wind
7 mph
7th windiest
Solar energy
3.43 kWh/m²
Travel score
6.5
out of 10

Alton is city in Madison County, Illinois, United States.

Density
623/km²
people per km²
Founded
1818

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

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 73°F in the first days to 61°F by the end.

A typical October day in Alton reaches about 67°F in the afternoon and slips back to 48°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 54°F and 79°F. Set against its neighbours, October runs about 12°F cooler than September and about 14°F warmer than November.

20°40°60°80°151015202531
Avg high (°F)Avg low (°F)
17453
27353
37352
47252
57252
67151
77151
87151
97050
107050
116949
126949
136849
146848
156748
166747
176647
186647
196547
206546
216446
226446
236445
246345
256345
266244
276244
286144
296143
306043
316042

How October really feels in Alton

Once humidity and wind are folded in, October 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

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

Alton weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 6th-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 October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 44% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 11% of October, with mostly cloudy or overcast conditions the remaining 44%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16535
26535
36436
46436
56337
66238
76139
86040
96040
105941
115842
125743
135743
145743
155743
165644
175545
185545
195446
205347
215248
225248
235149
245149
255050
264951
274951
284852
294852
304753
314753

Chance of precipitation in October

Any precipitation

Alton gets around 3.3 in of rain and snow over 8.4 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 27% and peaks near 30% on the wettest days, and about 0 day brings snow. The odds climb toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
123
222
322
422
523
623
723
824
925
1025
1126
1226
1327
1427
1528
1628
1728
1829
1929
2029
2129
2229
2330
2430
2530
2630
2730
2830
2930
3030
3129

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 80% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
16615118
26714118
36814117
46913117
57113106
67113106
77312105
87312105
9761194
10761194
11771193
12791083
13801082
14811072
15821071
16821071
1783971
1884961
1985960
2085960
2186860
2286860
2386860
2486860
2587850
2687850
2787850
2887850
2987850
3088840
3189740

Wind in October

Winds average 7 mph in October.

Across October, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 36 min at the start of October to 10 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over October. Sunrise moves from 6:02 AM to 6:33 AM, and sunset from 5:38 PM to 4:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:025:38
211.66:035:36
311.56:045:34
411.56:055:33
511.46:065:31
611.46:075:30
711.36:085:28
811.36:095:27
911.36:105:25
1011.26:115:24
1111.26:125:22
1211.16:135:21
1311.16:145:19
1411.06:155:18
1511.06:165:16
1611.06:175:15
1710.96:185:13
1810.96:195:12
1910.86:205:11
2010.86:215:09
2110.86:225:08
2210.76:235:07
2310.76:245:05
2410.66:255:04
2510.66:265:03
2610.66:285:01
2710.56:295:00
2810.56:304:59
2910.56:314:58
3010.46:324:57
3110.46:334:56

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 3.43 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 — October's 3.43 kWh/m² falls in the middle.

012345151015202531
Solar energy (kWh/m²)Level
14.2Bright
24.1Bright
34.1Bright
44.0Bright
54.0Moderate
63.9Moderate
73.9Moderate
83.8Moderate
93.8Moderate
103.7Moderate
113.7Moderate
123.6Moderate
133.6Moderate
143.5Moderate
153.5Moderate
163.4Moderate
173.4Moderate
183.4Moderate
193.3Moderate
203.3Moderate
213.2Moderate
223.2Moderate
233.1Moderate
243.1Moderate
253.0Moderate
263.0Moderate
272.9Moderate
282.9Moderate
292.9Moderate
302.8Moderate
312.8Moderate
Planning a trip in October

Hazard calendar for Alton

In seasonPeak

In October, Alton sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Alton sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is October a good time to visit Alton?

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

6.5
Sightseeing
2nd-best month of the year
3.1
Beach & pool
6th-best month of the year

October is a reasonable time to visit Alton for sightseeing.

What to pack for Alton in October

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

In October, Alton sees daytime highs around 67°F and nights near 48°F. Worth packing: rain gear. About 8 days see rain.

rain gear

UV index in Alton in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in 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 Alton in October

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in 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 Alton?

Alton sits at 38.9°N, 90.2°W, 492 ft above sea level, in United States. The nearest listed city is Upper Alton, 2.5 mi away.

Topography around Alton

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

Within 2 miles, the terrain around Alton has only modest variations in elevation — a maximum elevation change of 256 ft around an average of 476 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 636 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 801 ft.

The land around Alton is covered by trees (38%) and water (28%) within 2 miles, trees (41%) and cropland (28%) within 10 miles, and cropland (47%) and trees (39%) within 50 miles.

2 miles
256 ft
10 miles
636 ft
50 miles
801 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
October weather nearby: Upper Alton 2.5 mi · Godfrey 4.3 mi · Old Jamestown 6.8 mi · Spanish Lake 7.5 mi · Florissant 9.9 mi · Ferguson 12 mi · Hazelwood 13 mi · Granite City 13 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 Alton (38.8906°, -90.1843°, elevation 492 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).