S
M
T
W
T
F
S
30
92°
58°
31
85°
60°
1
68°
52°
2
69°
55°
3
64°
56°
4
73°
51°
5
77°
52°
6
76°
54°
7
85°
53°
8
91°
57°
9
91°
61°
10
94°
69°
11
89°
64°
12
81°
65°
13
76°
53°
14
85°
53°
15
87°
57°
16
75°
58°
17
76°
51°
18
82°
56°
19
90°
58°
20
83°
59°
21
89°
58°
22
92°
59°
23
90°
50°
24
95°
52°
25
90°
52°
26
85°
48°
27
83°
52°
28
81°
51°
29
82°
48°
30
81°
49°
1
82°
47°
2
78°
51°
3
84°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Clearlake Riviera
Clearlake Riviera's September 2026 forecast shows daily high temperatures ranging from 78° to 95°, with overnight lows between 47° and 59°. The average high for September is 85° with an average low of 53°. 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 Clearlake Riviera. See also: October | November | December.
