S
M
T
W
T
F
S
30
74°
51°
31
73°
51°
1
73°
49°
2
74°
49°
3
74°
52°
4
78°
56°
5
75°
56°
6
74°
51°
7
77°
52°
8
74°
56°
9
73°
49°
10
73°
49°
11
74°
53°
12
75°
53°
13
75°
46°
14
72°
55°
15
77°
56°
16
80°
54°
17
77°
46°
18
75°
43°
19
68°
43°
20
67°
44°
21
68°
43°
22
73°
52°
23
74°
52°
24
75°
44°
25
74°
40°
26
69°
41°
27
64°
40°
28
63°
39°
29
63°
40°
30
65°
38°
1
Hist. Avg.
68°
43°
2
Hist. Avg.
67°
42°
3
Hist. Avg.
67°
42°
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 63° to 80°, with overnight lows between 38° and 56°. The average high for September is 73° 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.
