S
M
T
W
T
F
S
30
76°
38°
31
88°
39°
1
83°
49°
2
75°
53°
3
63°
42°
4
65°
37°
5
69°
44°
6
65°
46°
7
68°
50°
8
76°
41°
9
85°
40°
10
89°
41°
11
75°
51°
12
85°
39°
13
59°
48°
14
65°
43°
15
73°
36°
16
79°
54°
17
73°
49°
18
76°
44°
19
80°
43°
20
82°
43°
21
85°
43°
22
82°
46°
23
76°
37°
24
88°
56°
25
70°
36°
26
64°
34°
27
65°
31°
28
69°
38°
29
73°
43°
30
71°
35°
1
74°
42°
2
66°
37°
3
69°
40°
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 64° to 88°, with overnight lows between 31° and 56°. The average high for September is 71° with an average low of 39°. 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.
