S
M
T
W
T
F
S
30
81°
66°
31
87°
67°
1
87°
67°
2
86°
67°
3
88°
68°
4
86°
68°
5
90°
67°
6
84°
59°
7
81°
60°
8
80°
60°
9
79°
55°
10
78°
51°
11
74°
51°
12
76°
50°
13
73°
52°
14
75°
50°
15
79°
56°
16
79°
55°
17
78°
55°
18
79°
56°
19
79°
55°
20
77°
54°
21
79°
56°
22
79°
56°
23
78°
55°
24
78°
55°
25
77°
54°
26
78°
52°
27
77°
53°
28
77°
53°
29
76°
52°
30
76°
53°
1
75°
52°
2
75°
52°
3
74°
50°
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 73° to 90°, with overnight lows between 50° and 68°. 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.
