S
M
T
W
T
F
S
30
77°
43°
31
72°
41°
1
63°
44°
2
64°
45°
3
70°
47°
4
73°
47°
5
73°
49°
6
71°
42°
7
63°
41°
8
61°
44°
9
61°
39°
10
62°
46°
11
64°
38°
12
60°
39°
13
60°
43°
14
62°
47°
15
63°
43°
16
60°
39°
17
59°
46°
18
63°
37°
19
66°
34°
20
57°
34°
21
55°
33°
22
53°
33°
23
53°
34°
24
54°
36°
25
54°
38°
26
56°
33°
27
54°
42°
28
54°
34°
29
55°
40°
30
58°
38°
1
56°
40°
2
60°
37°
3
61°
42°
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 53° to 77°, with overnight lows between 33° and 49°. The average high for September is 61° with an average low of 40°. 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.
