S
M
T
W
T
F
S
30
71°
62°
31
68°
65°
1
76°
67°
2
78°
66°
3
82°
62°
4
79°
61°
5
78°
58°
6
71°
58°
7
76°
54°
8
76°
64°
9
76°
61°
10
72°
50°
11
69°
53°
12
74°
59°
13
75°
56°
14
71°
56°
15
70°
55°
16
69°
53°
17
70°
54°
18
70°
53°
19
67°
52°
20
65°
42°
21
62°
55°
22
63°
55°
23
64°
54°
24
66°
55°
25
70°
54°
26
69°
52°
27
63°
53°
28
68°
53°
29
70°
55°
30
70°
55°
1
69°
54°
2
67°
51°
3
67°
48°
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 62° to 76°, with overnight lows between 42° and 64°. The average high for September is 69° 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 Oshawa. See also: October | November | December.
