S
M
T
W
T
F
S
30
95°
74°
31
94°
74°
1
93°
73°
2
95°
74°
3
95°
74°
4
94°
73°
5
94°
73°
6
93°
72°
7
94°
72°
8
94°
71°
9
95°
73°
10
95°
73°
11
94°
72°
12
95°
73°
13
94°
72°
14
92°
69°
15
93°
69°
16
94°
69°
17
95°
70°
18
93°
62°
19
88°
60°
20
83°
60°
21
85°
63°
22
88°
65°
23
90°
66°
24
90°
65°
25
89°
66°
26
89°
64°
27
88°
64°
28
87°
62°
29
81°
60°
30
82°
63°
1
87°
63°
2
87°
62°
3
86°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Brownsville
Brownsville's September 2026 forecast shows daily high temperatures ranging from 81° to 95°, with overnight lows between 60° and 74°. The average high for September is 91° with an average low of 68°. 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 Brownsville. See also: October | November | December.
