S
M
T
W
T
F
S
26
97°
75°
27
97°
78°
28
94°
76°
29
90°
73°
30
82°
71°
31
82°
68°
1
83°
65°
2
85°
61°
3
87°
60°
4
89°
65°
5
78°
70°
6
81°
69°
7
88°
67°
8
89°
67°
9
94°
75°
10
92°
77°
11
94°
76°
12
89°
76°
13
95°
77°
14
88°
73°
15
86°
75°
16
82°
66°
17
84°
61°
18
75°
68°
19
83°
63°
20
85°
62°
21
90°
63°
22
83°
58°
23
81°
64°
24
83°
66°
25
87°
64°
26
87°
62°
27
86°
60°
28
86°
67°
29
93°
69°
30
91°
71°
31
91°
67°
1
88°
62°
2
86°
61°
3
83°
63°
4
78°
62°
5
77°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in St. Joseph
St. Joseph's August 2026 forecast shows daily high temperatures ranging from 77° to 93°, with overnight lows between 58° and 71°. The average high for August is 85° with an average low of 64°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in St. Joseph. See also: September | October | November.