S
M
T
W
T
F
S
30
88°
77°
31
89°
77°
1
93°
79°
2
94°
79°
3
89°
79°
4
88°
78°
5
90°
80°
6
90°
78°
7
89°
77°
8
91°
78°
9
91°
76°
10
86°
78°
11
84°
74°
12
87°
76°
13
92°
74°
14
96°
74°
15
96°
72°
16
97°
66°
17
93°
67°
18
91°
72°
19
90°
72°
20
89°
71°
21
87°
68°
22
86°
67°
23
86°
65°
24
87°
65°
25
86°
67°
26
85°
66°
27
86°
69°
28
85°
69°
29
84°
68°
30
85°
69°
1
86°
69°
2
86°
68°
3
85°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Blue Mountain Beach
Blue Mountain Beach's September 2026 forecast shows daily high temperatures ranging from 84° to 97°, with overnight lows between 65° and 74°. The average high for September is 88° with an average low of 69°. 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 Blue Mountain Beach. See also: October | November | December.