S
M
T
W
T
F
S
26
83°
64°
27
86°
63°
28
86°
58°
29
79°
57°
30
78°
58°
31
79°
59°
1
80°
60°
2
79°
59°
3
78°
58°
4
77°
57°
5
81°
61°
6
Hist. Avg.
80°
61°
7
Hist. Avg.
80°
60°
8
Hist. Avg.
79°
60°
9
Hist. Avg.
79°
60°
10
Hist. Avg.
79°
60°
11
Hist. Avg.
79°
60°
12
Hist. Avg.
79°
60°
13
Hist. Avg.
79°
60°
14
Hist. Avg.
79°
60°
15
Hist. Avg.
79°
60°
16
Hist. Avg.
79°
60°
17
Hist. Avg.
79°
60°
18
Hist. Avg.
78°
60°
19
Hist. Avg.
78°
59°
20
Hist. Avg.
78°
59°
21
Hist. Avg.
78°
59°
22
Hist. Avg.
77°
58°
23
Hist. Avg.
77°
58°
24
Hist. Avg.
77°
58°
25
Hist. Avg.
77°
58°
26
Hist. Avg.
76°
57°
27
Hist. Avg.
76°
57°
28
Hist. Avg.
76°
57°
29
Hist. Avg.
76°
57°
30
Hist. Avg.
75°
56°
31
Hist. Avg.
75°
56°
1
Hist. Avg.
75°
56°
2
Hist. Avg.
75°
56°
3
Hist. Avg.
74°
55°
4
Hist. Avg.
74°
55°
5
Hist. Avg.
74°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
August Weather in St. Catharines
St. Catharines's August 2026 forecast shows daily high temperatures ranging from 77° to 86°, with overnight lows between 57° and 64°. The average high for August is 81° with an average low of 59°. 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 St. Catharines. See also: September | October | November.
