S
M
T
W
T
F
S
30
72°
53°
31
72°
52°
1
73°
50°
2
72°
55°
3
73°
50°
4
72°
52°
5
72°
54°
6
70°
52°
7
70°
50°
8
75°
55°
9
72°
48°
10
71°
48°
11
72°
55°
12
71°
52°
13
70°
46°
14
68°
55°
15
71°
57°
16
77°
55°
17
74°
46°
18
71°
44°
19
64°
43°
20
63°
44°
21
64°
43°
22
66°
49°
23
67°
46°
24
64°
43°
25
65°
42°
26
64°
41°
27
63°
42°
28
62°
41°
29
60°
40°
30
61°
47°
1
60°
39°
2
59°
36°
3
Hist. Avg.
63°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Clear Lake
Clear Lake's September 2026 forecast shows daily high temperatures ranging from 59° to 77°, with overnight lows between 36° and 57°. The average high for September is 68° with an average low of 48°. 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 Clear Lake. See also: October | November | December.
