S
M
T
W
T
F
S
30
88°
61°
31
88°
62°
1
87°
61°
2
86°
61°
3
86°
60°
4
83°
58°
5
82°
56°
6
79°
55°
7
82°
58°
8
85°
60°
9
86°
59°
10
84°
50°
11
75°
59°
12
82°
58°
13
83°
59°
14
84°
60°
15
85°
57°
16
82°
49°
17
72°
54°
18
80°
55°
19
71°
47°
20
71°
51°
21
Hist. Avg.
79°
46°
22
Hist. Avg.
79°
46°
23
Hist. Avg.
78°
46°
24
Hist. Avg.
78°
46°
25
Hist. Avg.
78°
45°
26
Hist. Avg.
77°
45°
27
Hist. Avg.
77°
45°
28
Hist. Avg.
76°
44°
29
Hist. Avg.
76°
44°
30
Hist. Avg.
75°
44°
1
Hist. Avg.
75°
43°
2
Hist. Avg.
74°
43°
3
Hist. Avg.
74°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Umatilla
Umatilla's September 2026 forecast shows daily high temperatures ranging from 71° to 88°, with overnight lows between 47° and 62°. The average high for September is 82° with an average low of 57°. 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 Umatilla. See also: October | November | December.
