S
M
T
W
T
F
S
30
87°
63°
31
83°
63°
1
83°
64°
2
84°
63°
3
83°
67°
4
84°
63°
5
87°
63°
6
83°
62°
7
82°
61°
8
81°
62°
9
81°
61°
10
83°
64°
11
85°
66°
12
80°
66°
13
83°
65°
14
85°
65°
15
Hist. Avg.
84°
58°
16
Hist. Avg.
84°
58°
17
Hist. Avg.
84°
58°
18
Hist. Avg.
83°
57°
19
Hist. Avg.
83°
57°
20
Hist. Avg.
83°
56°
21
Hist. Avg.
82°
56°
22
Hist. Avg.
82°
55°
23
Hist. Avg.
82°
55°
24
Hist. Avg.
81°
54°
25
Hist. Avg.
81°
54°
26
Hist. Avg.
80°
54°
27
Hist. Avg.
80°
53°
28
Hist. Avg.
80°
53°
29
Hist. Avg.
79°
52°
30
Hist. Avg.
79°
52°
1
Hist. Avg.
79°
51°
2
Hist. Avg.
78°
51°
3
Hist. Avg.
78°
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 80° to 87°, with overnight lows between 61° and 67°. The average high for September is 83° with an average low of 64°. 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.
