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
74°
45°
15
83°
63°
16
72°
67°
17
73°
59°
18
74°
60°
19
74°
60°
20
68°
57°
21
72°
55°
22
70°
55°
23
71°
57°
24
70°
54°
25
73°
53°
26
71°
55°
27
72°
54°
28
74°
55°
29
70°
48°
30
72°
56°
1
73°
54°
2
69°
53°
3
63°
52°
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 63° to 74°, with overnight lows between 48° and 67°. The average high for September is 71° with an average low of 56°. 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.
