S
M
T
W
T
F
S
31
79°
63°
1
79°
57°
2
79°
54°
3
75°
54°
4
70°
46°
5
70°
48°
6
70°
45°
7
72°
43°
8
75°
52°
9
77°
50°
10
84°
50°
11
86°
55°
12
91°
61°
13
95°
68°
14
95°
66°
15
91°
66°
16
91°
63°
17
91°
63°
18
81°
63°
19
82°
61°
20
68°
63°
21
75°
61°
22
82°
61°
23
73°
59°
24
75°
61°
25
75°
52°
26
82°
54°
27
84°
55°
28
86°
57°
29
86°
55°
30
88°
57°
1
84°
61°
2
88°
59°
3
88°
63°
4
86°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Monticello
Monticello's September 2025 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Monticello. See also: October | November | December.
