S
M
T
W
T
F
S
30
87°
69°
31
88°
67°
1
82°
68°
2
82°
67°
3
83°
68°
4
83°
68°
5
82°
67°
6
82°
67°
7
87°
66°
8
82°
61°
9
82°
60°
10
81°
64°
11
81°
61°
12
86°
60°
13
85°
66°
14
85°
59°
15
82°
57°
16
78°
59°
17
79°
58°
18
82°
59°
19
84°
58°
20
84°
58°
21
83°
61°
22
84°
62°
23
83°
57°
24
80°
58°
25
83°
55°
26
82°
61°
27
82°
61°
28
81°
60°
29
82°
60°
30
82°
59°
1
79°
60°
2
81°
60°
3
81°
58°
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 78° to 88°, with overnight lows between 55° and 69°. The average high for September is 83° with an average low of 62°. 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.
