S
M
T
W
T
F
S
30
91°
59°
31
91°
58°
1
90°
59°
2
90°
61°
3
91°
60°
4
90°
57°
5
89°
54°
6
87°
52°
7
82°
56°
8
84°
57°
9
88°
58°
10
88°
59°
11
89°
58°
12
87°
56°
13
88°
56°
14
88°
55°
15
84°
54°
16
82°
52°
17
84°
54°
18
88°
57°
19
88°
58°
20
87°
56°
21
85°
56°
22
81°
55°
23
79°
51°
24
81°
54°
25
81°
51°
26
80°
50°
27
79°
50°
28
78°
48°
29
79°
49°
30
78°
51°
1
78°
57°
2
83°
56°
3
85°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Pleasanton
Pleasanton's September 2026 forecast shows daily high temperatures ranging from 78° to 91°, with overnight lows between 48° and 61°. The average high for September is 85° 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 Pleasanton. See also: October | November | December.
