S
M
T
W
T
F
S
30
83°
62°
31
82°
59°
1
83°
58°
2
82°
58°
3
81°
57°
4
81°
57°
5
82°
62°
6
81°
62°
7
83°
59°
8
82°
59°
9
82°
60°
10
83°
63°
11
84°
63°
12
86°
62°
13
85°
58°
14
80°
63°
15
86°
62°
16
85°
62°
17
84°
61°
18
85°
57°
19
81°
59°
20
82°
52°
21
84°
51°
22
77°
49°
23
74°
51°
24
Hist. Avg.
79°
54°
25
Hist. Avg.
79°
53°
26
Hist. Avg.
78°
53°
27
Hist. Avg.
78°
52°
28
Hist. Avg.
78°
52°
29
Hist. Avg.
77°
52°
30
Hist. Avg.
77°
51°
1
Hist. Avg.
76°
51°
2
Hist. Avg.
76°
50°
3
Hist. Avg.
76°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Hillsboro
Hillsboro's September 2026 forecast shows daily high temperatures ranging from 74° to 86°, with overnight lows between 49° and 63°. The average high for September is 82° with an average low of 59°. 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 Hillsboro. See also: October | November | December.
