S
M
T
W
T
F
S
30
82°
63°
31
75°
62°
1
82°
62°
2
78°
58°
3
74°
54°
4
77°
59°
5
81°
61°
6
81°
61°
7
82°
60°
8
82°
61°
9
81°
61°
10
78°
59°
11
72°
58°
12
72°
50°
13
75°
52°
14
72°
48°
15
73°
47°
16
72°
45°
17
70°
48°
18
69°
46°
19
68°
43°
20
68°
44°
21
69°
44°
22
68°
45°
23
72°
46°
24
76°
50°
25
77°
54°
26
77°
52°
27
69°
45°
28
75°
52°
29
69°
42°
30
68°
52°
1
70°
39°
2
74°
39°
3
70°
37°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Algonquin
Algonquin's September 2026 forecast shows daily high temperatures ranging from 68° to 82°, with overnight lows between 37° and 63°. The average high for September is 74° with an average low of 51°. 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 Algonquin. See also: October | November | December.
