S
M
T
W
T
F
S
30
85°
68°
31
89°
67°
1
84°
68°
2
85°
69°
3
84°
69°
4
87°
70°
5
87°
68°
6
88°
67°
7
85°
66°
8
84°
67°
9
84°
65°
10
83°
66°
11
85°
66°
12
87°
68°
13
85°
69°
14
86°
64°
15
82°
64°
16
Hist. Avg.
83°
65°
17
Hist. Avg.
82°
64°
18
Hist. Avg.
82°
64°
19
Hist. Avg.
82°
64°
20
Hist. Avg.
82°
63°
21
Hist. Avg.
81°
63°
22
Hist. Avg.
81°
62°
23
Hist. Avg.
81°
62°
24
Hist. Avg.
80°
62°
25
Hist. Avg.
80°
61°
26
Hist. Avg.
80°
61°
27
Hist. Avg.
80°
60°
28
Hist. Avg.
79°
60°
29
Hist. Avg.
79°
59°
30
Hist. Avg.
79°
59°
1
Hist. Avg.
79°
58°
2
Hist. Avg.
78°
58°
3
Hist. Avg.
78°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Northwest
Northwest's September 2026 forecast shows daily high temperatures ranging from 82° to 89°, with overnight lows between 64° and 70°. The average high for September is 85° with an average low of 67°. 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 Northwest. See also: October | November | December.
