S
M
T
W
T
F
S
30
96°
72°
31
88°
63°
1
84°
62°
2
86°
62°
3
82°
63°
4
82°
65°
5
86°
64°
6
77°
60°
7
87°
63°
8
86°
62°
9
87°
64°
10
87°
64°
11
88°
63°
12
86°
61°
13
84°
59°
14
82°
59°
15
85°
61°
16
86°
63°
17
85°
59°
18
74°
53°
19
74°
56°
20
81°
58°
21
80°
53°
22
83°
58°
23
82°
52°
24
71°
52°
25
70°
49°
26
73°
51°
27
74°
54°
28
73°
55°
29
69°
55°
30
76°
54°
1
79°
49°
2
72°
54°
3
79°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in St. Joseph
St. Joseph's September 2026 forecast shows daily high temperatures ranging from 69° to 96°, with overnight lows between 49° and 72°. The average high for September is 81° with an average low of 59°. 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. Joseph. See also: October | November | December.
