S
M
T
W
T
F
S
30
105°
81°
31
105°
81°
1
105°
80°
2
106°
82°
3
106°
83°
4
106°
83°
5
105°
75°
6
104°
78°
7
105°
80°
8
106°
82°
9
104°
81°
10
107°
79°
11
106°
82°
12
103°
82°
13
101°
80°
14
102°
81°
15
101°
79°
16
102°
78°
17
97°
77°
18
94°
76°
19
93°
75°
20
94°
73°
21
93°
74°
22
95°
74°
23
96°
75°
24
100°
68°
25
95°
75°
26
94°
74°
27
94°
75°
28
93°
75°
29
94°
74°
30
95°
75°
1
95°
74°
2
93°
74°
3
92°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in McAllen
McAllen's September 2026 forecast shows daily high temperatures ranging from 92° to 106°, with overnight lows between 68° and 82°. The average high for September is 97° with an average low of 76°. 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 McAllen. See also: October | November | December.
