S
M
T
W
T
F
S
26
54°
37°
27
69°
38°
28
70°
46°
29
48°
39°
30
48°
35°
1
N/A
2
45°
32°
3
58°
44°
4
66°
51°
5
59°
41°
6
46°
38°
7
49°
36°
8
51°
40°
9
55°
41°
10
58°
44°
11
58°
44°
12
60°
46°
13
61°
45°
14
58°
41°
15
60°
46°
16
59°
45°
17
61°
52°
18
67°
53°
19
66°
53°
20
67°
54°
21
70°
55°
22
66°
55°
23
68°
53°
24
63°
49°
25
62°
49°
26
64°
56°
27
70°
57°
28
71°
56°
29
66°
54°
30
65°
52°
31
68°
49°
1
64°
51°
2
65°
52°
3
65°
51°
4
66°
49°
5
66°
52°
6
67°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Sarnia
Sarnia's May 2026 forecast shows daily high temperatures ranging from 45° to 71°, with overnight lows between 32° and 57°. The average high for May is 62° with an average low of 48°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Sarnia. See also: June | July | August.
