S
M
T
W
T
F
S
30
83°
59°
31
83°
62°
1
80°
62°
2
83°
58°
3
82°
52°
4
75°
53°
5
74°
60°
6
77°
60°
7
81°
54°
8
74°
55°
9
73°
57°
10
74°
60°
11
76°
59°
12
81°
60°
13
80°
59°
14
81°
58°
15
80°
55°
16
74°
57°
17
71°
49°
18
73°
49°
19
70°
47°
20
68°
46°
21
67°
47°
22
68°
54°
23
69°
47°
24
71°
48°
25
71°
54°
26
72°
54°
27
74°
55°
28
75°
52°
29
74°
49°
30
70°
49°
1
68°
50°
2
73°
51°
3
66°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Union
Union's September 2026 forecast shows daily high temperatures ranging from 66° to 83°, with overnight lows between 43° and 62°. The average high for September is 75° 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 September weather will actually feel in Union. See also: October | November | December.
