S
M
T
W
T
F
S
26
76°
60°
27
80°
59°
28
90°
57°
29
100°
63°
30
84°
67°
31
83°
64°
1
82°
59°
2
89°
58°
3
96°
66°
4
89°
69°
5
81°
66°
6
77°
59°
7
80°
51°
8
87°
55°
9
90°
64°
10
89°
62°
11
89°
62°
12
95°
63°
13
100°
66°
14
101°
68°
15
88°
71°
16
85°
64°
17
81°
60°
18
80°
63°
19
74°
55°
20
75°
55°
21
72°
52°
22
73°
51°
23
72°
53°
24
75°
55°
25
74°
58°
26
76°
55°
27
75°
56°
28
74°
55°
29
69°
57°
30
72°
56°
31
70°
54°
1
71°
55°
2
70°
53°
3
72°
54°
4
68°
51°
5
71°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Longueil-Sainte-Marie
Longueil-Sainte-Marie's August 2026 forecast shows daily high temperatures ranging from 68° to 85°, with overnight lows between 51° and 64°. The average high for August is 74° with an average low of 56°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Longueil-Sainte-Marie. See also: September | October | November.