S
M
T
W
T
F
S
26
75°
48°
27
74°
48°
28
81°
52°
29
82°
52°
30
81°
46°
31
71°
44°
1
71°
44°
2
73°
48°
3
80°
49°
4
80°
50°
5
72°
45°
6
71°
44°
7
74°
49°
8
80°
52°
9
76°
50°
10
72°
46°
11
72°
48°
12
73°
47°
13
73°
47°
14
74°
48°
15
73°
49°
16
72°
49°
17
70°
48°
18
70°
44°
19
76°
50°
20
79°
51°
21
80°
49°
22
79°
47°
23
78°
52°
24
79°
42°
25
73°
39°
26
68°
40°
27
69°
41°
28
73°
45°
29
75°
45°
30
70°
46°
31
67°
45°
1
67°
43°
2
66°
39°
3
67°
43°
4
71°
47°
5
65°
38°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Forest Grove
Forest Grove's August 2026 forecast shows daily high temperatures ranging from 65° to 82°, with overnight lows between 38° and 52°. The average high for August is 74° with an average low of 46°. 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 Forest Grove. See also: September | October | November.