S
M
T
W
T
F
S
30
79°
62°
31
80°
64°
1
82°
62°
2
80°
55°
3
79°
54°
4
77°
55°
5
78°
56°
6
79°
56°
7
83°
58°
8
83°
63°
9
84°
59°
10
82°
54°
11
78°
61°
12
79°
58°
13
81°
52°
14
77°
52°
15
75°
50°
16
76°
52°
17
77°
59°
18
81°
50°
19
76°
57°
20
77°
53°
21
82°
56°
22
77°
58°
23
81°
58°
24
75°
57°
25
79°
57°
26
81°
56°
27
81°
56°
28
80°
55°
29
81°
55°
30
80°
56°
1
80°
54°
2
79°
47°
3
79°
45°
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 75° to 84°, with overnight lows between 45° and 64°. The average high for September is 79° with an average low of 56°. 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.
