S
M
T
W
T
F
S
30
84°
69°
31
84°
69°
1
83°
67°
2
84°
69°
3
84°
70°
4
83°
69°
5
82°
68°
6
83°
69°
7
82°
68°
8
83°
69°
9
83°
70°
10
82°
70°
11
83°
69°
12
83°
69°
13
82°
68°
14
82°
69°
15
83°
70°
16
83°
69°
17
82°
69°
18
83°
68°
19
82°
67°
20
83°
68°
21
82°
69°
22
83°
70°
23
82°
69°
24
83°
70°
25
83°
69°
26
84°
69°
27
83°
68°
28
83°
69°
29
82°
68°
30
83°
69°
1
83°
69°
2
82°
68°
3
83°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Diego
San Diego's September 2026 forecast shows daily high temperatures ranging from 82° to 84°, with overnight lows between 67° and 70°. The average high for September is 83° with an average low of 69°. 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 San Diego. See also: October | November | December.
