S
M
T
W
T
F
S
30
79°
54°
31
81°
56°
1
86°
66°
2
89°
64°
3
90°
58°
4
82°
52°
5
77°
54°
6
78°
59°
7
77°
57°
8
82°
56°
9
80°
60°
10
81°
53°
11
78°
54°
12
78°
55°
13
79°
52°
14
77°
49°
15
72°
47°
16
72°
46°
17
73°
48°
18
72°
50°
19
76°
56°
20
83°
52°
21
82°
52°
22
77°
49°
23
72°
48°
24
68°
47°
25
66°
47°
26
67°
46°
27
68°
46°
28
69°
51°
29
73°
49°
30
70°
43°
1
66°
46°
2
Hist. Avg.
71°
49°
3
Hist. Avg.
70°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Walla Walla
Walla Walla's September 2026 forecast shows daily high temperatures ranging from 66° to 90°, with overnight lows between 43° and 66°. The average high for September is 76° with an average low of 52°. 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 Walla Walla. See also: October | November | December.
