S
M
T
W
T
F
S
30
82°
58°
31
86°
60°
1
87°
62°
2
86°
63°
3
85°
62°
4
83°
58°
5
84°
60°
6
84°
62°
7
85°
57°
8
81°
61°
9
85°
61°
10
84°
60°
11
84°
61°
12
83°
62°
13
84°
58°
14
79°
55°
15
78°
55°
16
79°
54°
17
80°
59°
18
82°
58°
19
82°
60°
20
81°
59°
21
76°
58°
22
81°
59°
23
80°
58°
24
81°
53°
25
75°
51°
26
74°
50°
27
Hist. Avg.
77°
52°
28
Hist. Avg.
77°
52°
29
Hist. Avg.
76°
52°
30
Hist. Avg.
76°
51°
1
Hist. Avg.
76°
51°
2
Hist. Avg.
76°
50°
3
Hist. Avg.
75°
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 87°, with overnight lows between 50° and 63°. The average high for September is 82° with an average low of 58°. 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.
