S
M
T
W
T
F
S
26
62°
43°
27
56°
44°
28
52°
36°
29
55°
36°
30
54°
37°
1
54°
37°
2
70°
32°
3
72°
48°
4
61°
37°
5
52°
30°
6
50°
30°
7
63°
34°
8
73°
41°
9
63°
41°
10
63°
37°
11
72°
34°
12
73°
55°
13
75°
45°
14
81°
52°
15
90°
52°
16
81°
48°
17
81°
57°
18
62°
45°
19
55°
39°
20
63°
46°
21
66°
49°
22
62°
51°
23
71°
51°
24
77°
55°
25
79°
59°
26
82°
58°
27
77°
59°
28
78°
57°
29
76°
56°
30
78°
57°
31
75°
53°
1
78°
58°
2
70°
56°
3
73°
56°
4
74°
58°
5
78°
59°
6
75°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Fairfax
Fairfax's May 2026 forecast shows daily high temperatures ranging from 55° to 82°, with overnight lows between 39° and 59°. The average high for May is 72° with an average low of 54°. 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 Fairfax. See also: June | July | August.