S
M
T
W
T
F
S
30
72°
66°
31
71°
66°
1
81°
68°
2
82°
68°
3
82°
63°
4
78°
60°
5
74°
58°
6
72°
58°
7
75°
59°
8
72°
59°
9
76°
62°
10
76°
57°
11
71°
57°
12
71°
56°
13
70°
55°
14
68°
54°
15
71°
50°
16
74°
56°
17
74°
52°
18
65°
48°
19
70°
49°
20
73°
55°
21
73°
55°
22
72°
53°
23
70°
53°
24
67°
52°
25
71°
54°
26
69°
51°
27
64°
46°
28
59°
48°
29
59°
46°
30
58°
44°
1
57°
46°
2
58°
49°
3
64°
48°
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 57° to 82°, with overnight lows between 44° and 68°. The average high for September is 70° with an average low of 54°. 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.
