S
M
T
W
T
F
S
26
85°
54°
27
86°
55°
28
87°
53°
29
84°
56°
30
88°
59°
31
91°
60°
1
90°
56°
2
88°
57°
3
91°
57°
4
93°
58°
5
92°
56°
6
91°
57°
7
88°
56°
8
92°
61°
9
90°
61°
10
91°
61°
11
91°
60°
12
88°
61°
13
90°
61°
14
90°
60°
15
85°
60°
16
88°
59°
17
87°
60°
18
86°
60°
19
89°
59°
20
90°
60°
21
89°
59°
22
81°
59°
23
88°
60°
24
87°
59°
25
84°
58°
26
78°
56°
27
78°
58°
28
83°
58°
29
83°
57°
30
81°
58°
31
77°
58°
1
78°
57°
2
80°
57°
3
80°
56°
4
79°
56°
5
80°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Heppner
Heppner's August 2026 forecast shows daily high temperatures ranging from 77° to 93°, with overnight lows between 53° and 61°. The average high for August is 86° with an average low of 58°. 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 Heppner. See also: September | October | November.