S
M
T
W
T
F
S
30
77°
50°
31
72°
49°
1
69°
59°
2
71°
59°
3
69°
54°
4
75°
52°
5
75°
53°
6
75°
53°
7
82°
55°
8
89°
57°
9
85°
59°
10
84°
56°
11
81°
57°
12
83°
57°
13
83°
56°
14
85°
56°
15
86°
55°
16
82°
53°
17
83°
54°
18
79°
56°
19
84°
55°
20
84°
56°
21
83°
56°
22
83°
55°
23
77°
56°
24
80°
54°
25
84°
56°
26
85°
57°
27
86°
58°
28
85°
57°
29
84°
56°
30
83°
57°
1
84°
56°
2
81°
56°
3
76°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Larkspur
Larkspur's September 2026 forecast shows daily high temperatures ranging from 69° to 89°, with overnight lows between 52° and 59°. The average high for September is 82° with an average low of 56°. 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 Larkspur. See also: October | November | December.
