S
M
T
W
T
F
S
30
78°
59°
31
77°
58°
1
78°
59°
2
78°
57°
3
76°
50°
4
68°
48°
5
67°
57°
6
68°
58°
7
75°
57°
8
75°
57°
9
76°
56°
10
70°
51°
11
74°
53°
12
74°
56°
13
73°
56°
14
73°
55°
15
72°
51°
16
70°
45°
17
65°
52°
18
68°
47°
19
65°
46°
20
66°
44°
21
61°
42°
22
60°
50°
23
62°
46°
24
61°
43°
25
60°
41°
26
59°
42°
27
60°
49°
28
66°
42°
29
64°
40°
30
58°
40°
1
59°
42°
2
59°
38°
3
58°
38°
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 58° to 78°, with overnight lows between 38° and 59°. The average high for September is 68° with an average low of 49°. 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.
