S
M
T
W
T
F
S
30
95°
59°
31
96°
57°
1
95°
56°
2
94°
56°
3
94°
57°
4
96°
60°
5
96°
61°
6
95°
57°
7
94°
57°
8
91°
58°
9
94°
57°
10
92°
53°
11
89°
54°
12
89°
52°
13
90°
52°
14
89°
51°
15
88°
57°
16
87°
54°
17
93°
53°
18
91°
51°
19
88°
54°
20
91°
53°
21
93°
54°
22
92°
55°
23
90°
57°
24
85°
57°
25
Hist. Avg.
90°
56°
26
Hist. Avg.
90°
56°
27
Hist. Avg.
89°
56°
28
Hist. Avg.
89°
56°
29
Hist. Avg.
88°
56°
30
Hist. Avg.
88°
56°
1
Hist. Avg.
88°
55°
2
Hist. Avg.
87°
55°
3
Hist. Avg.
87°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Vacaville
Vacaville's September 2026 forecast shows daily high temperatures ranging from 85° to 96°, with overnight lows between 51° and 61°. The average high for September is 92° with an average low of 55°. 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 Vacaville. See also: October | November | December.
