S
M
T
W
T
F
S
30
83°
70°
31
91°
73°
1
91°
68°
2
88°
69°
3
84°
72°
4
86°
68°
5
88°
67°
6
83°
63°
7
76°
64°
8
73°
61°
9
75°
58°
10
74°
54°
11
70°
54°
12
69°
53°
13
69°
54°
14
72°
53°
15
76°
59°
16
76°
57°
17
74°
58°
18
75°
59°
19
75°
58°
20
74°
57°
21
75°
59°
22
76°
59°
23
76°
58°
24
75°
58°
25
74°
57°
26
75°
55°
27
74°
56°
28
74°
55°
29
72°
54°
30
73°
55°
1
72°
55°
2
72°
54°
3
71°
53°
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 69° to 91°, with overnight lows between 53° and 72°. The average high for September is 76° with an average low of 59°. 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.
