S
M
T
W
T
F
S
30
71°
38°
31
71°
45°
1
77°
48°
2
81°
49°
3
84°
48°
4
83°
47°
5
79°
48°
6
73°
47°
7
77°
46°
8
78°
43°
9
69°
45°
10
70°
46°
11
67°
43°
12
68°
41°
13
67°
36°
14
69°
38°
15
74°
43°
16
74°
42°
17
76°
40°
18
74°
44°
19
77°
45°
20
76°
47°
21
73°
44°
22
72°
44°
23
68°
43°
24
74°
43°
25
73°
42°
26
69°
41°
27
63°
42°
28
66°
43°
29
62°
40°
30
64°
42°
1
69°
43°
2
70°
42°
3
Hist. Avg.
64°
37°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Diamond Lake
Diamond Lake's September 2026 forecast shows daily high temperatures ranging from 62° to 84°, with overnight lows between 36° and 49°. The average high for September is 72° with an average low of 43°. 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 Diamond Lake. See also: October | November | December.
