S
M
T
W
T
F
S
30
81°
67°
31
91°
70°
1
93°
74°
2
94°
74°
3
93°
75°
4
92°
74°
5
86°
72°
6
81°
64°
7
82°
63°
8
85°
62°
9
80°
67°
10
77°
61°
11
82°
58°
12
87°
64°
13
75°
54°
14
71°
52°
15
86°
65°
16
74°
65°
17
84°
67°
18
73°
63°
19
71°
63°
20
69°
60°
21
68°
58°
22
64°
55°
23
67°
58°
24
71°
57°
25
67°
49°
26
71°
48°
27
71°
52°
28
72°
50°
29
72°
59°
30
67°
60°
1
74°
56°
2
70°
58°
3
71°
53°
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 67° to 74°, with overnight lows between 48° and 60°. The average high for September is 71° with an average low of 54°. 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.
