S
M
T
W
T
F
S
30
78°
51°
31
87°
52°
1
87°
67°
2
79°
62°
3
72°
53°
4
75°
48°
5
75°
57°
6
71°
54°
7
78°
58°
8
82°
51°
9
88°
48°
10
87°
57°
11
81°
56°
12
82°
59°
13
63°
54°
14
74°
53°
15
76°
53°
16
80°
58°
17
81°
59°
18
86°
62°
19
85°
63°
20
82°
61°
21
82°
62°
22
81°
62°
23
80°
60°
24
77°
55°
25
70°
60°
26
70°
59°
27
71°
54°
28
68°
51°
29
68°
50°
30
68°
49°
1
70°
58°
2
73°
56°
3
74°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mattawa
Mattawa's September 2026 forecast shows daily high temperatures ranging from 63° to 86°, with overnight lows between 49° and 63°. The average high for September is 76° 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 Mattawa. See also: October | November | December.
