S
M
T
W
T
F
S
30
71°
54°
31
70°
53°
1
70°
54°
2
69°
54°
3
70°
52°
4
69°
49°
5
65°
49°
6
68°
53°
7
67°
50°
8
69°
52°
9
67°
51°
10
68°
48°
11
67°
47°
12
67°
48°
13
66°
49°
14
64°
50°
15
65°
46°
16
64°
45°
17
62°
44°
18
62°
47°
19
64°
48°
20
63°
47°
21
62°
45°
22
63°
46°
23
63°
49°
24
62°
47°
25
62°
46°
26
64°
49°
27
65°
50°
28
65°
50°
29
Hist. Avg.
60°
48°
30
Hist. Avg.
60°
48°
1
Hist. Avg.
60°
47°
2
Hist. Avg.
60°
47°
3
Hist. Avg.
59°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Northampton
Northampton's September 2026 forecast shows daily high temperatures ranging from 62° to 71°, with overnight lows between 44° and 54°. The average high for September is 66° with an average low of 49°. 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 Northampton. See also: October | November | December.