S
M
T
W
T
F
S
30
83°
67°
31
88°
69°
1
91°
69°
2
95°
76°
3
90°
73°
4
89°
71°
5
84°
68°
6
79°
58°
7
81°
53°
8
81°
56°
9
77°
69°
10
75°
55°
11
80°
50°
12
85°
64°
13
72°
52°
14
73°
63°
15
79°
65°
16
74°
68°
17
74°
61°
18
77°
63°
19
81°
61°
20
73°
57°
21
72°
59°
22
70°
56°
23
71°
54°
24
73°
54°
25
73°
53°
26
74°
55°
27
75°
56°
28
75°
56°
29
73°
55°
30
72°
56°
1
73°
54°
2
73°
52°
3
72°
54°
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 70° to 81°, with overnight lows between 52° and 68°. The average high for September is 74° with an average low of 58°. 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.
