S
M
T
W
T
F
S
30
81°
69°
31
91°
72°
1
94°
77°
2
96°
78°
3
92°
79°
4
93°
78°
5
83°
73°
6
79°
71°
7
80°
66°
8
87°
66°
9
80°
71°
10
76°
65°
11
81°
61°
12
88°
68°
13
75°
56°
14
72°
53°
15
85°
68°
16
72°
68°
17
73°
66°
18
74°
66°
19
82°
63°
20
67°
62°
21
68°
64°
22
69°
62°
23
70°
64°
24
68°
61°
25
71°
63°
26
72°
61°
27
70°
62°
28
71°
62°
29
68°
54°
30
71°
61°
1
72°
60°
2
65°
59°
3
62°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Millennium Park
Millennium Park's September 2026 forecast shows daily high temperatures ranging from 62° to 82°, with overnight lows between 54° and 68°. The average high for September is 70° with an average low of 62°. 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 Millennium Park. See also: October | November | December.
