S
M
T
W
T
F
S
30
82°
61°
31
85°
65°
1
86°
66°
2
84°
65°
3
86°
58°
4
80°
57°
5
78°
58°
6
80°
64°
7
85°
64°
8
83°
63°
9
78°
62°
10
80°
63°
11
84°
62°
12
84°
63°
13
83°
63°
14
84°
62°
15
83°
62°
16
83°
61°
17
81°
57°
18
76°
53°
19
74°
51°
20
74°
51°
21
72°
50°
22
72°
52°
23
73°
52°
24
77°
51°
25
74°
57°
26
78°
58°
27
77°
57°
28
77°
56°
29
78°
55°
30
77°
55°
1
74°
53°
2
76°
56°
3
76°
55°
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 72° to 86°, with overnight lows between 50° and 66°. The average high for September is 79° with an average low of 58°. 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.
