S
M
T
W
T
F
S
31
81°
67°
1
88°
65°
2
81°
60°
3
82°
53°
4
84°
67°
5
86°
68°
6
89°
72°
7
86°
72°
8
81°
72°
9
86°
70°
10
93°
71°
11
91°
70°
12
90°
69°
13
89°
69°
14
87°
67°
15
88°
67°
16
87°
64°
17
86°
65°
18
89°
67°
19
84°
69°
20
90°
69°
21
90°
65°
22
83°
64°
23
89°
70°
24
91°
71°
25
92°
70°
26
91°
70°
27
88°
69°
28
89°
70°
29
90°
70°
30
88°
69°
1
89°
69°
2
88°
70°
3
87°
69°
4
88°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
June Weather in O'Fallon
O'Fallon's June 2026 forecast shows daily high temperatures ranging from 81° to 93°, with overnight lows between 64° and 72°. The average high for June is 88° with an average low of 69°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how June weather will actually feel in O'Fallon. See also: July | August | September.
