S
M
T
W
T
F
S
30
83°
58°
31
83°
61°
1
87°
63°
2
88°
63°
3
88°
62°
4
89°
64°
5
82°
60°
6
80°
60°
7
80°
54°
8
81°
55°
9
85°
60°
10
85°
64°
11
79°
61°
12
80°
59°
13
84°
58°
14
83°
60°
15
81°
57°
16
79°
57°
17
79°
55°
18
78°
56°
19
77°
53°
20
75°
50°
21
80°
55°
22
77°
54°
23
77°
54°
24
78°
53°
25
79°
54°
26
79°
54°
27
78°
53°
28
79°
54°
29
79°
53°
30
78°
53°
1
77°
52°
2
77°
48°
3
74°
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 74° to 85°, with overnight lows between 43° and 64°. The average high for September is 79° with an average low of 55°. 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.
