S
M
T
W
T
F
S
30
87°
67°
31
87°
67°
1
86°
66°
2
85°
63°
3
80°
62°
4
80°
62°
5
79°
60°
6
79°
59°
7
83°
64°
8
83°
64°
9
82°
65°
10
85°
65°
11
86°
64°
12
86°
65°
13
84°
65°
14
84°
62°
15
85°
61°
16
84°
57°
17
79°
58°
18
78°
56°
19
77°
55°
20
77°
55°
21
78°
59°
22
80°
60°
23
81°
59°
24
81°
56°
25
76°
56°
26
76°
55°
27
78°
55°
28
79°
57°
29
80°
57°
30
80°
56°
1
74°
58°
2
77°
58°
3
79°
57°
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 87°, with overnight lows between 55° and 67°. The average high for September is 81° 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.
