S
M
T
W
T
F
S
30
74°
61°
31
74°
60°
1
75°
62°
2
77°
64°
3
75°
64°
4
81°
65°
5
82°
64°
6
79°
63°
7
78°
62°
8
74°
61°
9
75°
62°
10
73°
62°
11
74°
61°
12
75°
60°
13
78°
61°
14
78°
61°
15
79°
60°
16
78°
60°
17
76°
59°
18
76°
60°
19
74°
59°
20
76°
60°
21
79°
57°
22
79°
53°
23
78°
45°
24
70°
46°
25
72°
52°
26
77°
49°
27
72°
56°
28
76°
58°
29
78°
58°
30
77°
52°
1
78°
46°
2
68°
53°
3
66°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Plainfield
Plainfield's September 2026 forecast shows daily high temperatures ranging from 66° to 82°, with overnight lows between 45° and 65°. The average high for September is 76° with an average low of 58°. 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 Plainfield. See also: October | November | December.
