S
M
T
W
T
F
S
26
79°
49°
27
81°
61°
28
62°
55°
29
64°
42°
30
67°
37°
1
64°
40°
2
61°
40°
3
78°
37°
4
81°
51°
5
71°
46°
6
62°
38°
7
68°
36°
8
75°
45°
9
81°
51°
10
70°
46°
11
78°
40°
12
82°
48°
13
75°
46°
14
75°
41°
15
83°
61°
16
78°
69°
17
86°
63°
18
78°
65°
19
76°
61°
20
67°
56°
21
73°
54°
22
67°
63°
23
74°
63°
24
81°
56°
25
81°
58°
26
78°
63°
27
82°
63°
28
84°
63°
29
76°
62°
30
82°
55°
31
80°
54°
1
82°
56°
2
80°
57°
3
81°
60°
4
79°
60°
5
81°
62°
6
82°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Hillsboro
Hillsboro's May 2026 forecast shows daily high temperatures ranging from 76° to 84°, with overnight lows between 54° and 63°. The average high for May is 81° with an average low of 60°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Hillsboro. See also: June | July | August.