S
M
T
W
T
F
S
30
72°
50°
31
71°
50°
1
70°
53°
2
71°
52°
3
71°
54°
4
72°
53°
5
72°
50°
6
71°
51°
7
70°
49°
8
69°
48°
9
69°
54°
10
70°
48°
11
67°
48°
12
71°
47°
13
72°
54°
14
74°
49°
15
72°
54°
16
74°
54°
17
74°
53°
18
73°
54°
19
74°
52°
20
74°
49°
21
67°
52°
22
66°
48°
23
67°
51°
24
66°
49°
25
62°
45°
26
69°
42°
27
68°
43°
28
59°
42°
29
58°
44°
30
59°
43°
1
60°
46°
2
Hist. Avg.
63°
44°
3
Hist. Avg.
62°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mississauga
Mississauga's September 2026 forecast shows daily high temperatures ranging from 58° to 74°, with overnight lows between 42° and 54°. The average high for September is 69° 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 Mississauga. See also: October | November | December.
