S
M
T
W
T
F
S
30
81°
70°
31
91°
70°
1
93°
72°
2
93°
73°
3
93°
72°
4
95°
71°
5
89°
66°
6
83°
62°
7
82°
63°
8
86°
65°
9
89°
65°
10
83°
60°
11
82°
59°
12
76°
57°
13
81°
59°
14
80°
58°
15
81°
57°
16
77°
52°
17
81°
58°
18
73°
57°
19
75°
58°
20
78°
57°
21
77°
57°
22
76°
55°
23
73°
54°
24
75°
54°
25
78°
55°
26
77°
50°
27
67°
44°
28
66°
43°
29
65°
46°
30
66°
42°
1
65°
45°
2
69°
51°
3
65°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in LaSalle
LaSalle's September 2026 forecast shows daily high temperatures ranging from 65° to 95°, with overnight lows between 42° and 72°. The average high for September is 78° with an average low of 56°. 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 LaSalle. See also: October | November | December.
