S
M
T
W
T
F
S
30
93°
71°
31
91°
67°
1
87°
63°
2
87°
61°
3
84°
59°
4
85°
62°
5
95°
59°
6
90°
72°
7
100°
75°
8
103°
78°
9
107°
80°
10
100°
78°
11
97°
73°
12
89°
68°
13
87°
67°
14
87°
65°
15
82°
64°
16
81°
65°
17
81°
64°
18
81°
64°
19
84°
64°
20
82°
64°
21
79°
59°
22
81°
60°
23
83°
60°
24
84°
62°
25
86°
63°
26
84°
64°
27
82°
62°
28
84°
61°
29
84°
61°
30
80°
62°
1
82°
62°
2
77°
58°
3
76°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Rancho Bernardo
Rancho Bernardo's September 2026 forecast shows daily high temperatures ranging from 76° to 86°, with overnight lows between 58° and 64°. The average high for September is 82° with an average low of 61°. 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 Rancho Bernardo. See also: October | November | December.
