S
M
T
W
T
F
S
30
93°
65°
31
94°
71°
1
96°
71°
2
97°
73°
3
98°
74°
4
98°
74°
5
95°
76°
6
87°
67°
7
87°
70°
8
90°
70°
9
92°
72°
10
84°
66°
11
82°
64°
12
87°
65°
13
89°
69°
14
86°
65°
15
83°
63°
16
82°
61°
17
84°
63°
18
83°
60°
19
80°
59°
20
78°
57°
21
84°
61°
22
77°
61°
23
81°
60°
24
83°
62°
25
83°
62°
26
82°
61°
27
83°
61°
28
83°
60°
29
82°
61°
30
82°
61°
1
81°
58°
2
79°
49°
3
68°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mount Washington
Mount Washington's September 2026 forecast shows daily high temperatures ranging from 68° to 92°, with overnight lows between 47° and 72°. The average high for September is 83° with an average low of 62°. 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 Mount Washington. See also: October | November | December.
