S
M
T
W
T
F
S
30
68°
65°
31
76°
68°
1
88°
69°
2
94°
70°
3
80°
63°
4
76°
63°
5
74°
62°
6
73°
58°
7
77°
54°
8
82°
54°
9
76°
68°
10
76°
58°
11
72°
52°
12
81°
54°
13
73°
59°
14
66°
51°
15
75°
54°
16
69°
60°
17
69°
62°
18
68°
57°
19
64°
55°
20
67°
58°
21
61°
48°
22
66°
46°
23
69°
49°
24
70°
42°
25
64°
38°
26
66°
49°
27
67°
52°
28
68°
49°
29
73°
48°
30
71°
54°
1
70°
61°
2
58°
50°
3
62°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sarnia
Sarnia's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Sarnia. See also: October | November | December.
