S
M
T
W
T
F
S
30
88°
71°
31
91°
68°
1
94°
71°
2
96°
72°
3
95°
72°
4
96°
72°
5
97°
70°
6
87°
69°
7
85°
65°
8
85°
66°
9
88°
65°
10
92°
68°
11
92°
68°
12
88°
66°
13
88°
64°
14
89°
67°
15
87°
61°
16
79°
64°
17
78°
63°
18
77°
63°
19
78°
64°
20
78°
64°
21
79°
63°
22
79°
64°
23
82°
63°
24
78°
62°
25
76°
62°
26
78°
61°
27
81°
59°
28
79°
52°
29
73°
51°
30
73°
51°
1
74°
54°
2
74°
58°
3
72°
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 72° to 97°, with overnight lows between 51° and 72°. The average high for September is 83° with an average low of 63°. 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.
