Port Isabel (TX) Weather & Climate: Best Time to Visit

Depending on the time of the year, temperatures range from very warm to pleasant in Port Isabel. Average daytime temperatures reach a very warm 33°C (91°F) in August. In January, the coolest month of the year, temperatures drop to a pleasant 20°C (68°F).

At night, temperatures range from around 26°C (79°F) in August to 12°C (54°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Generally, Port Isabel has a moderate amount of precipitation, averaging 687 mm (27 in) of rainfall annually. Port Isabel can be quite wet during September, receiving approximately 171 mm (6.7 in) of precipitation over 14 rainy days.

In contrast, during the driest month (August), you will experience much drier conditions, with 25 mm (1 in) of precipitation spread across 6 rainy days. For more details, please visit our Port Isabel Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

Port Isabel can be enjoyed more throughout the sunniest month of July under a blue sky, with approximately 10.9 hours of sunshine daily. In contrast, the city experiences much darker days in January, with only 4.4 hours of sunlight per day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is high throughout the year in Port Isabel.

The city experiences its highest humidity in January, reaching 78%. In July, the humidity drops to its lowest level at 73%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year