S
M
T
W
T
F
S
30
82°
65°
31
85°
58°
1
86°
55°
2
77°
58°
3
78°
63°
4
84°
62°
5
85°
54°
6
81°
54°
7
76°
58°
8
78°
61°
9
77°
55°
10
76°
59°
11
75°
55°
12
74°
51°
13
74°
50°
14
73°
51°
15
73°
56°
16
74°
58°
17
80°
59°
18
81°
59°
19
82°
56°
20
75°
57°
21
81°
56°
22
75°
48°
23
80°
47°
24
71°
46°
25
69°
47°
26
69°
48°
27
69°
45°
28
Hist. Avg.
74°
50°
29
Hist. Avg.
73°
50°
30
Hist. Avg.
73°
49°
1
Hist. Avg.
72°
49°
2
Hist. Avg.
72°
48°
3
Hist. Avg.
72°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mercer
Mercer's September 2026 forecast shows daily high temperatures ranging from 69° to 86°, with overnight lows between 45° and 65°. The average high for September is 77° with an average low of 55°. 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 Mercer. See also: October | November | December.
