S
M
T
W
T
F
S
30
93°
67°
31
92°
67°
1
88°
64°
2
87°
59°
3
82°
58°
4
82°
62°
5
85°
66°
6
89°
63°
7
90°
64°
8
85°
63°
9
87°
63°
10
87°
57°
11
80°
56°
12
80°
55°
13
79°
57°
14
81°
61°
15
85°
62°
16
80°
61°
17
82°
60°
18
77°
52°
19
76°
51°
20
75°
54°
21
75°
54°
22
77°
58°
23
80°
58°
24
81°
59°
25
82°
50°
26
81°
49°
27
74°
51°
28
72°
49°
29
72°
49°
30
72°
48°
1
Hist. Avg.
74°
51°
2
Hist. Avg.
74°
50°
3
Hist. Avg.
74°
50°
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 93°, with overnight lows between 48° and 67°. The average high for September is 82° with an average low of 58°. 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.
