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Today Hourly 7 days 30 days September
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September 2026 Weather | O'Fallon, Missouri

Today 9/1
Hot Day
Day 100°
Night 73°
1
Wed 9/2
Hot Day
Day 99°
Night 73°
8
Thu 9/3
Hot Day
Day 100°
Night 73°
8
Fri 9/4
Hot Day
Day 99°
Night 72°
9
Sat 9/5
Hot Day
Day 97°
Night 72°
25
Sun 9/6
Hot Day
Day 97°
Night 70°
55
Mon 9/7
Cloudy Weather
Day 91°
Night 70°
23
Tue 9/8
Cloudy Weather
Day 90°
Night 66°
1
Wed 9/9
Sunny Weather
Day 90°
Night 68°
1
Thu 9/10
Sunny Weather
Day 86°
Night 64°
2
Fri 9/11
Cloudy Weather
Day 84°
Night 57°
1
Sat 9/12
Cloudy Weather
Day 82°
Night 59°
1
Sun 9/13
Cloudy Weather
Day 84°
Night 61°
5
Mon 9/14
Cloudy Weather
Day 81°
Night 57°
25
Tue 9/15
Cloudy Weather
Day 82°
Night 63°
10
Wed 9/16
Cloudy Weather
Day 84°
Night 63°
Thu 9/17
Sunny Weather
Day 84°
Night 63°
Fri 9/18
Cloudy Weather
Day 82°
Night 61°
Sat 9/19
Cloudy Weather
Day 82°
Night 63°
Sun 9/20
Cloudy Weather
Day 84°
Night 63°
Mon 9/21
Sunny Weather
Day 82°
Night 63°
Tue 9/22
Sunny Weather
Day 82°
Night 61°
Wed 9/23
Sunny Weather
Day 82°
Night 61°
Thu 9/24
Sunny Weather
Day 82°
Night 61°
Fri 9/25
Cloudy Weather
Day 82°
Night 59°
Sat 9/26
Sunny Weather
Day 82°
Night 61°
Sun 9/27
Sunny Weather
Day 82°
Night 59°
Mon 9/28
Sunny Weather
Day 82°
Night 59°
Tue 9/29
Cloudy Weather
Day 81°
Night 57°
Wed 9/30
Cloudy Weather
Day 81°
Night 57°

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