S
M
T
W
T
F
S
26
90°
80°
27
89°
78°
28
90°
79°
29
91°
81°
30
91°
80°
31
90°
79°
1
90°
79°
2
90°
80°
3
90°
79°
4
90°
79°
5
91°
77°
6
89°
79°
7
91°
80°
8
91°
79°
9
91°
79°
10
91°
81°
11
90°
80°
12
90°
81°
13
92°
81°
14
94°
84°
15
94°
82°
16
92°
81°
17
91°
81°
18
91°
81°
19
90°
81°
20
89°
80°
21
90°
79°
22
89°
80°
23
91°
80°
24
92°
79°
25
91°
81°
26
92°
80°
27
88°
81°
28
87°
82°
29
87°
82°
30
88°
81°
31
87°
82°
1
87°
82°
2
88°
81°
3
87°
82°
4
87°
81°
5
88°
82°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in St John
St John's August 2026 forecast shows daily high temperatures ranging from 87° to 94°, with overnight lows between 79° and 84°. The average high for August is 90° with an average low of 81°. 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 John. See also: September | October | November.