S
M
T
W
T
F
S
30
90°
66°
31
94°
69°
1
95°
68°
2
96°
70°
3
97°
71°
4
97°
72°
5
93°
68°
6
83°
61°
7
85°
60°
8
88°
64°
9
92°
71°
10
82°
68°
11
81°
70°
12
80°
68°
13
88°
64°
14
84°
65°
15
91°
69°
16
88°
70°
17
84°
64°
18
78°
59°
19
74°
57°
20
71°
52°
21
71°
54°
22
77°
56°
23
78°
56°
24
75°
53°
25
78°
58°
26
80°
57°
27
80°
58°
28
79°
58°
29
79°
57°
30
78°
57°
1
75°
54°
2
73°
55°
3
78°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Cincinnati
Cincinnati's September 2026 forecast shows daily high temperatures ranging from 71° to 91°, with overnight lows between 52° and 70°. The average high for September is 79° with an average low of 59°. 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 Cincinnati. See also: October | November | December.