S
M
T
W
T
F
S
30
93°
64°
31
98°
63°
1
99°
70°
2
99°
74°
3
98°
73°
4
99°
73°
5
100°
73°
6
88°
70°
7
86°
61°
8
93°
59°
9
92°
69°
10
79°
67°
11
85°
65°
12
92°
65°
13
86°
63°
14
87°
60°
15
99°
66°
16
93°
72°
17
98°
70°
18
97°
70°
19
97°
70°
20
92°
70°
21
72°
65°
22
74°
58°
23
70°
56°
24
71°
58°
25
74°
57°
26
72°
56°
27
75°
56°
28
81°
53°
29
83°
48°
30
92°
64°
1
91°
67°
2
74°
55°
3
77°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Bethalto
Bethalto's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Bethalto. See also: October | November | December.
