S
M
T
W
T
F
S
28
95°
73°
29
96°
74°
30
98°
73°
1
98°
74°
2
98°
75°
3
96°
71°
4
94°
70°
5
88°
69°
6
86°
68°
7
90°
69°
8
90°
68°
9
85°
66°
10
93°
72°
11
93°
71°
12
91°
71°
13
91°
70°
14
92°
71°
15
92°
71°
16
91°
72°
17
93°
73°
18
94°
73°
19
93°
72°
20
93°
73°
21
94°
73°
22
93°
74°
23
94°
73°
24
92°
72°
25
91°
73°
26
93°
73°
27
95°
74°
28
95°
74°
29
94°
73°
30
95°
73°
31
93°
72°
1
93°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
July Weather in O'Fallon
O'Fallon's July 2026 forecast shows daily high temperatures ranging from 85° to 98°, with overnight lows between 66° and 75°. The average high for July is 93° with an average low of 72°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how July weather will actually feel in O'Fallon. See also: August | September | October.
