S
M
T
W
T
F
S
30
92°
76°
31
93°
75°
1
93°
75°
2
92°
74°
3
89°
75°
4
90°
75°
5
90°
74°
6
92°
75°
7
92°
74°
8
91°
74°
9
92°
72°
10
88°
71°
11
89°
72°
12
88°
72°
13
90°
73°
14
91°
74°
15
90°
73°
16
87°
74°
17
90°
72°
18
90°
70°
19
87°
73°
20
87°
73°
21
86°
68°
22
86°
72°
23
87°
72°
24
89°
71°
25
90°
72°
26
88°
72°
27
86°
71°
28
86°
72°
29
88°
71°
30
87°
70°
1
85°
71°
2
88°
65°
3
84°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Upper Grand Lagoon
Upper Grand Lagoon's September 2026 forecast shows daily high temperatures ranging from 84° to 93°, with overnight lows between 65° and 76°. The average high for September is 89° with an average low of 72°. 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 Upper Grand Lagoon. See also: October | November | December.
