S
M
T
W
T
F
S
30
88°
71°
31
91°
70°
1
96°
71°
2
96°
74°
3
97°
74°
4
97°
75°
5
97°
74°
6
95°
72°
7
80°
71°
8
85°
69°
9
90°
66°
10
92°
67°
11
94°
70°
12
81°
72°
13
90°
69°
14
92°
71°
15
82°
73°
16
87°
70°
17
89°
69°
18
94°
70°
19
89°
70°
20
88°
69°
21
91°
68°
22
81°
69°
23
72°
63°
24
68°
59°
25
77°
51°
26
80°
50°
27
81°
52°
28
81°
55°
29
83°
57°
30
84°
61°
1
85°
63°
2
84°
66°
3
83°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Pendleton
Pendleton's September 2026 forecast shows daily high temperatures ranging from 77° to 85°, with overnight lows between 50° and 66°. The average high for September is 82° 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 September weather will actually feel in Pendleton. See also: October | November | December.