S
M
T
W
T
F
S
30
76°
61°
31
82°
63°
1
81°
57°
2
82°
56°
3
75°
55°
4
76°
57°
5
76°
63°
6
79°
62°
7
82°
57°
8
75°
61°
9
74°
62°
10
76°
61°
11
77°
60°
12
78°
59°
13
75°
59°
14
72°
54°
15
73°
53°
16
72°
52°
17
72°
54°
18
73°
58°
19
75°
58°
20
74°
59°
21
76°
55°
22
72°
50°
23
70°
56°
24
69°
57°
25
74°
52°
26
73°
49°
27
Hist. Avg.
69°
48°
28
Hist. Avg.
69°
47°
29
Hist. Avg.
68°
47°
30
Hist. Avg.
68°
46°
1
Hist. Avg.
68°
46°
2
Hist. Avg.
67°
46°
3
Hist. Avg.
67°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Riverhead Town
Riverhead Town's September 2026 forecast shows daily high temperatures ranging from 69° to 82°, with overnight lows between 49° and 63°. The average high for September is 75° 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 Riverhead Town. See also: October | November | December.
