S
M
T
W
T
F
S
26
84°
55°
27
82°
53°
28
83°
50°
29
85°
50°
30
84°
47°
31
82°
49°
1
80°
48°
2
78°
53°
3
80°
54°
4
85°
55°
5
86°
56°
6
86°
54°
7
85°
46°
8
84°
45°
9
83°
46°
10
83°
44°
11
76°
45°
12
76°
48°
13
79°
48°
14
83°
49°
15
83°
46°
16
84°
46°
17
83°
45°
18
81°
47°
19
80°
44°
20
81°
47°
21
77°
45°
22
74°
43°
23
75°
42°
24
74°
44°
25
75°
47°
26
72°
44°
27
72°
47°
28
73°
43°
29
73°
43°
30
74°
45°
31
74°
51°
1
76°
53°
2
79°
54°
3
82°
47°
4
82°
51°
5
80°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Saint Helens
Saint Helens's August 2026 forecast shows daily high temperatures ranging from 72° to 86°, with overnight lows between 42° and 56°. The average high for August is 80° 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 August weather will actually feel in Saint Helens. See also: September | October | November.