S
M
T
W
T
F
S
30
72°
48°
31
73°
49°
1
68°
48°
2
67°
46°
3
68°
45°
4
68°
44°
5
68°
55°
6
72°
55°
7
Hist. Avg.
69°
47°
8
Hist. Avg.
69°
47°
9
Hist. Avg.
68°
47°
10
Hist. Avg.
68°
47°
11
Hist. Avg.
68°
46°
12
Hist. Avg.
68°
46°
13
Hist. Avg.
67°
46°
14
Hist. Avg.
67°
46°
15
Hist. Avg.
67°
46°
16
Hist. Avg.
67°
46°
17
Hist. Avg.
66°
46°
18
Hist. Avg.
66°
46°
19
Hist. Avg.
66°
46°
20
Hist. Avg.
65°
46°
21
Hist. Avg.
65°
46°
22
Hist. Avg.
65°
45°
23
Hist. Avg.
64°
45°
24
Hist. Avg.
64°
45°
25
Hist. Avg.
64°
45°
26
Hist. Avg.
63°
45°
27
Hist. Avg.
63°
45°
28
Hist. Avg.
63°
45°
29
Hist. Avg.
62°
44°
30
Hist. Avg.
62°
44°
1
Hist. Avg.
62°
44°
2
Hist. Avg.
61°
44°
3
Hist. Avg.
61°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Friday Harbor
Friday Harbor's September 2026 forecast shows daily high temperatures ranging from 67° to 73°, with overnight lows between 44° and 55°. The average high for September is 70° with an average low of 49°. 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 Friday Harbor. See also: October | November | December.
