S
M
T
W
T
F
S
30
78°
60°
31
78°
61°
1
77°
62°
2
77°
58°
3
76°
51°
4
68°
49°
5
68°
57°
6
70°
60°
7
76°
59°
8
75°
58°
9
71°
51°
10
72°
58°
11
74°
57°
12
74°
59°
13
75°
59°
14
74°
58°
15
74°
53°
16
72°
52°
17
68°
54°
18
72°
49°
19
65°
46°
20
63°
45°
21
60°
44°
22
62°
54°
23
64°
51°
24
64°
45°
25
61°
44°
26
61°
52°
27
67°
53°
28
68°
48°
29
69°
46°
30
63°
47°
1
59°
48°
2
66°
43°
3
58°
42°
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 58° to 78°, with overnight lows between 42° and 62°. The average high for September is 69° with an average low of 52°. 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.
