S
M
T
W
T
F
S
30
91°
73°
31
90°
75°
1
89°
74°
2
88°
74°
3
86°
72°
4
86°
73°
5
88°
72°
6
89°
73°
7
90°
74°
8
89°
73°
9
90°
73°
10
89°
72°
11
89°
73°
12
88°
73°
13
89°
72°
14
88°
73°
15
86°
73°
16
85°
72°
17
84°
71°
18
84°
68°
19
85°
70°
20
84°
71°
21
83°
68°
22
85°
70°
23
84°
70°
24
85°
67°
25
86°
68°
26
85°
70°
27
85°
69°
28
86°
70°
29
84°
69°
30
85°
66°
1
Hist. Avg.
83°
66°
2
Hist. Avg.
82°
66°
3
Hist. Avg.
82°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Darien
Darien's September 2026 forecast shows daily high temperatures ranging from 83° to 91°, with overnight lows between 66° and 75°. The average high for September is 87° with an average low of 71°. 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 Darien. See also: October | November | December.
