S
M
T
W
T
F
S
30
96°
73°
31
96°
73°
1
95°
74°
2
94°
73°
3
93°
74°
4
94°
75°
5
92°
74°
6
93°
74°
7
94°
75°
8
95°
75°
9
95°
74°
10
92°
75°
11
94°
75°
12
94°
74°
13
93°
74°
14
94°
72°
15
92°
72°
16
90°
73°
17
90°
72°
18
91°
74°
19
90°
74°
20
93°
73°
21
92°
74°
22
93°
73°
23
93°
71°
24
94°
69°
25
92°
69°
26
92°
73°
27
93°
72°
28
Hist. Avg.
90°
70°
29
Hist. Avg.
90°
70°
30
Hist. Avg.
90°
70°
1
Hist. Avg.
90°
70°
2
Hist. Avg.
90°
70°
3
Hist. Avg.
90°
69°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Harlingen
Harlingen's September 2026 forecast shows daily high temperatures ranging from 90° to 96°, with overnight lows between 69° and 75°. The average high for September is 93° with an average low of 73°. 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 Harlingen. See also: October | November | December.
