S
M
T
W
T
F
S
30
88°
55°
31
78°
58°
1
78°
53°
2
80°
61°
3
76°
61°
4
79°
52°
5
85°
49°
6
85°
57°
7
90°
53°
8
96°
53°
9
103°
61°
10
107°
67°
11
94°
60°
12
89°
62°
13
82°
52°
14
89°
50°
15
89°
54°
16
77°
58°
17
77°
57°
18
86°
51°
19
90°
55°
20
82°
58°
21
79°
57°
22
82°
54°
23
92°
52°
24
94°
56°
25
87°
59°
26
83°
51°
27
79°
58°
28
86°
51°
29
98°
53°
30
95°
54°
1
95°
56°
2
95°
57°
3
101°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Vacaville
Vacaville's September 2026 forecast shows daily high temperatures ranging from 95° to 101°, with overnight lows between 56° and 61°. The average high for September is 97° with an average low of 58°. 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.
