S
M
T
W
T
F
S
30
79°
53°
31
81°
63°
1
68°
59°
2
72°
63°
3
76°
59°
4
77°
59°
5
72°
53°
6
76°
50°
7
78°
55°
8
77°
54°
9
78°
58°
10
79°
56°
11
79°
50°
12
72°
49°
13
75°
51°
14
77°
52°
15
72°
49°
16
73°
54°
17
77°
52°
18
68°
48°
19
70°
46°
20
72°
50°
21
75°
54°
22
76°
54°
23
76°
52°
24
75°
51°
25
74°
50°
26
74°
51°
27
75°
52°
28
74°
50°
29
73°
46°
30
64°
42°
1
63°
42°
2
64°
49°
3
71°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Amherst
Amherst's September 2026 forecast shows daily high temperatures ranging from 63° to 81°, with overnight lows between 42° and 63°. The average high for September is 74° with an average low of 52°. 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 Amherst. See also: October | November | December.