S
M
T
W
T
F
S
30
88°
71°
31
91°
68°
1
96°
71°
2
96°
71°
3
96°
73°
4
96°
72°
5
94°
70°
6
89°
66°
7
85°
65°
8
85°
66°
9
88°
65°
10
92°
68°
11
87°
65°
12
84°
62°
13
83°
60°
14
86°
61°
15
84°
64°
16
79°
64°
17
78°
63°
18
82°
64°
19
79°
63°
20
78°
59°
21
78°
57°
22
79°
59°
23
79°
58°
24
83°
63°
25
83°
62°
26
76°
61°
27
75°
62°
28
75°
61°
29
76°
60°
30
78°
60°
1
74°
59°
2
74°
58°
3
75°
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 74° to 96°, with overnight lows between 57° and 73°. 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.
