S
M
T
W
T
F
S
30
80°
54°
31
79°
55°
1
72°
60°
2
75°
59°
3
74°
59°
4
75°
54°
5
79°
55°
6
78°
54°
7
90°
55°
8
97°
60°
9
101°
66°
10
100°
70°
11
92°
58°
12
80°
58°
13
77°
54°
14
86°
56°
15
78°
55°
16
74°
57°
17
74°
60°
18
82°
56°
19
82°
56°
20
81°
55°
21
69°
55°
22
76°
55°
23
89°
55°
24
83°
54°
25
85°
60°
26
76°
53°
27
75°
55°
28
79°
52°
29
92°
54°
30
91°
58°
1
90°
54°
2
90°
56°
3
94°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Vallejo
Vallejo's September 2026 forecast shows daily high temperatures ranging from 94° to 94°, with overnight lows between 59° and 59°. The average high for September is 94° 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 Vallejo. See also: October | November | December.
