S
M
T
W
T
F
S
30
80°
53°
31
70°
54°
1
71°
61°
2
75°
60°
3
73°
54°
4
72°
55°
5
76°
52°
6
67°
52°
7
68°
53°
8
67°
49°
9
67°
53°
10
71°
51°
11
68°
49°
12
67°
50°
13
66°
49°
14
68°
53°
15
69°
47°
16
64°
47°
17
63°
46°
18
62°
46°
19
62°
47°
20
63°
47°
21
63°
49°
22
64°
46°
23
67°
54°
24
69°
48°
25
68°
54°
26
70°
52°
27
69°
44°
28
62°
44°
29
59°
52°
30
62°
52°
1
63°
51°
2
65°
50°
3
61°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Oshawa
Oshawa's September 2026 forecast shows daily high temperatures ranging from 59° to 80°, with overnight lows between 43° and 61°. The average high for September is 67° with an average low of 50°. 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 Oshawa. See also: October | November | December.
