S
M
T
W
T
F
S
30
86°
55°
31
85°
53°
1
84°
54°
2
83°
53°
3
83°
52°
4
82°
51°
5
82°
52°
6
83°
56°
7
82°
55°
8
84°
53°
9
83°
53°
10
83°
54°
11
84°
55°
12
83°
59°
13
83°
59°
14
88°
58°
15
88°
59°
16
87°
59°
17
86°
58°
18
88°
59°
19
88°
60°
20
89°
59°
21
87°
57°
22
86°
56°
23
86°
56°
24
85°
57°
25
86°
58°
26
85°
58°
27
82°
58°
28
Hist. Avg.
85°
56°
29
Hist. Avg.
84°
56°
30
Hist. Avg.
84°
56°
1
Hist. Avg.
84°
56°
2
Hist. Avg.
84°
56°
3
Hist. Avg.
84°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Vallejo
Vallejo's September 2026 forecast shows daily high temperatures ranging from 82° to 89°, with overnight lows between 51° and 60°. The average high for September is 85° 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 Vallejo. See also: October | November | December.
