S
M
T
W
T
F
S
30
94°
73°
31
92°
75°
1
89°
76°
2
89°
76°
3
89°
76°
4
92°
78°
5
91°
78°
6
94°
75°
7
90°
75°
8
91°
75°
9
92°
76°
10
93°
74°
11
91°
74°
12
93°
75°
13
91°
74°
14
94°
77°
15
92°
77°
16
91°
76°
17
91°
75°
18
88°
70°
19
88°
71°
20
88°
72°
21
88°
71°
22
87°
70°
23
85°
71°
24
84°
70°
25
86°
69°
26
86°
69°
27
83°
68°
28
82°
69°
29
82°
70°
30
84°
69°
1
85°
68°
2
86°
71°
3
86°
71°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Umatilla
Umatilla's September 2026 forecast shows daily high temperatures ranging from 82° to 88°, with overnight lows between 68° and 72°. The average high for September is 86° with an average low of 70°. 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.
