S
M
T
W
T
F
S
30
74°
54°
31
75°
60°
1
74°
62°
2
80°
61°
3
76°
52°
4
74°
52°
5
72°
53°
6
72°
54°
7
75°
58°
8
79°
57°
9
79°
59°
10
80°
53°
11
73°
54°
12
72°
57°
13
72°
50°
14
70°
51°
15
68°
50°
16
69°
49°
17
70°
55°
18
73°
47°
19
69°
48°
20
70°
47°
21
72°
48°
22
69°
54°
23
74°
55°
24
76°
56°
25
73°
55°
26
75°
56°
27
74°
55°
28
76°
52°
29
73°
52°
30
72°
55°
1
73°
53°
2
75°
44°
3
73°
42°
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 68° to 80°, with overnight lows between 42° and 62°. The average high for September is 73° with an average low of 53°. 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.
