S
M
T
W
T
F
S
30
81°
54°
31
N/A
1
67°
58°
2
68°
59°
3
70°
61°
4
78°
57°
5
71°
55°
6
75°
52°
7
76°
55°
8
74°
54°
9
77°
59°
10
76°
57°
11
75°
56°
12
75°
54°
13
74°
52°
14
71°
53°
15
70°
51°
16
72°
55°
17
75°
53°
18
67°
50°
19
68°
47°
20
71°
52°
21
74°
55°
22
75°
55°
23
75°
54°
24
74°
52°
25
73°
50°
26
74°
52°
27
73°
53°
28
73°
51°
29
71°
47°
30
63°
43°
1
61°
43°
2
63°
49°
3
69°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Hillsborough
Hillsborough's September 2026 forecast shows daily high temperatures ranging from 61° to 78°, with overnight lows between 43° and 61°. The average high for September is 72° with an average low of 53°. 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 Hillsborough. See also: October | November | December.
