S
M
T
W
T
F
S
27
68°
47°
28
70°
48°
29
71°
48°
30
71°
47°
1
70°
48°
2
70°
48°
3
68°
47°
4
67°
48°
5
69°
47°
6
68°
47°
7
67°
46°
8
68°
46°
9
66°
42°
10
63°
44°
11
64°
43°
12
66°
41°
13
65°
42°
14
60°
43°
15
62°
42°
16
60°
40°
17
59°
40°
18
62°
41°
19
63°
43°
20
64°
39°
21
63°
39°
22
60°
38°
23
61°
29°
24
60°
35°
25
48°
40°
26
60°
38°
27
59°
34°
28
56°
32°
29
46°
30°
30
45°
28°
31
44°
28°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
October Weather in Alton
Alton's October 2026 forecast shows daily high temperatures ranging from 44° to 71°, with overnight lows between 28° and 48°. The average high for October is 62° with an average low of 41°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how October weather will actually feel in Alton. See also: November | December | January.