Temperature for September
In Harlingen, TX during September the average high temperature is 90.6°F. The hottest day on record was September 4, 2011 when the temperature hit 107.1°F.

In Harlingen, TX during September the average high temperature is 90.6°F. The hottest day on record was September 4, 2011 when the temperature hit 107.1°F.
In September the average monthly rainfall in Harlingen, TX is 1.32 inches with rain usually falling on between 6 and 7 days. 1943 was the driest September with only 0.00 inches of rain falling, and 1998 was the wettest September with 11.04 inches of rain. The wettest single day in September was 10 September 1998 when 3.47 inches of rain fell.
There are thunderstorms on between 2 and 3 days in September.