S
M
T
W
T
F
S
30
67°
56°
31
68°
56°
1
67°
55°
2
66°
56°
3
63°
56°
4
64°
55°
5
67°
56°
6
65°
55°
7
68°
56°
8
69°
56°
9
68°
55°
10
69°
54°
11
66°
54°
12
68°
55°
13
70°
55°
14
69°
54°
15
69°
54°
16
68°
53°
17
68°
53°
18
66°
52°
19
63°
52°
20
64°
53°
21
68°
53°
22
69°
52°
23
67°
53°
24
67°
52°
25
68°
52°
26
68°
51°
27
69°
52°
28
69°
53°
29
68°
52°
30
68°
51°
1
66°
51°
2
66°
52°
3
68°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Half Moon Bay
Half Moon Bay's September 2026 forecast shows daily high temperatures ranging from 63° to 70°, with overnight lows between 51° and 56°. The average high for September is 67° with an average low of 54°. 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 Half Moon Bay. See also: October | November | December.
