S
M
T
W
T
F
S
30
71°
52°
31
70°
58°
1
71°
55°
2
69°
53°
3
71°
53°
4
76°
58°
5
69°
51°
6
69°
51°
7
70°
52°
8
70°
51°
9
69°
52°
10
69°
51°
11
70°
54°
12
72°
53°
13
75°
54°
14
76°
53°
15
75°
58°
16
76°
59°
17
76°
55°
18
74°
50°
19
69°
48°
20
72°
56°
21
72°
49°
22
67°
51°
23
68°
54°
24
64°
55°
25
62°
51°
26
62°
52°
27
61°
48°
28
61°
47°
29
62°
54°
30
61°
56°
1
62°
54°
2
63°
46°
3
62°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Alki
Alki's September 2026 forecast shows daily high temperatures ranging from 61° to 76°, with overnight lows between 45° and 59°. The average high for September is 69° with an average low of 53°. 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 Alki. See also: October | November | December.
