S
M
T
W
T
F
S
30
100°
75°
31
100°
74°
1
100°
76°
2
100°
73°
3
98°
72°
4
99°
77°
5
99°
73°
6
100°
73°
7
101°
71°
8
101°
77°
9
98°
76°
10
93°
76°
11
97°
77°
12
101°
76°
13
99°
74°
14
95°
73°
15
94°
69°
16
89°
66°
17
88°
65°
18
89°
67°
19
84°
62°
20
85°
62°
21
84°
61°
22
89°
67°
23
89°
67°
24
83°
66°
25
78°
66°
26
82°
65°
27
82°
65°
28
84°
64°
29
83°
65°
30
84°
56°
1
74°
52°
2
74°
53°
3
72°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in St. Jo
St. Jo's September 2026 forecast shows daily high temperatures ranging from 72° to 101°, with overnight lows between 52° and 77°. The average high for September is 87° with an average low of 66°. 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 St. Jo. See also: October | November | December.
