S
M
T
W
T
F
S
30
87°
69°
31
88°
68°
1
83°
68°
2
84°
67°
3
84°
64°
4
85°
64°
5
84°
63°
6
87°
65°
7
88°
66°
8
89°
66°
9
89°
65°
10
88°
67°
11
87°
56°
12
82°
64°
13
88°
55°
14
83°
56°
15
82°
58°
16
88°
60°
17
88°
63°
18
87°
63°
19
87°
56°
20
84°
53°
21
78°
56°
22
78°
56°
23
77°
57°
24
79°
59°
25
76°
58°
26
76°
57°
27
75°
54°
28
78°
52°
29
81°
51°
30
81°
57°
1
82°
58°
2
83°
46°
3
82°
46°
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 75° to 89°, with overnight lows between 46° and 69°. The average high for September is 83° 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 September weather will actually feel in Union. See also: October | November | December.
