Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September's presence marks an average high-temperature of a still hot 86.2°F (30.1°C), subtly varied from August's 88°F (31.1°C). In Port Isabel, the nightly September temperatures experience a slight descent from daily highs to an average low of 80.4°F (26.9°C).Heat index
September's average heat index is evaluated at a fiery hot 96.8°F (36°C). Exercise extra preventive actions, heat cramps and heat exhaustion are plausible. Continuous activity could result in heatstroke.Take into consideration that the heat index values are calculated for shade and light wind conditions. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'feels like' or 'real feel', unifies temperature and humidity readings to offer a comprehensive feel of warmth. Factors including metabolic differences, physical activity, and clothing are additional elements that influence the individual's temperature experience. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Normally, the human body cools itself through perspiration, which removes excessive heat by evaporating sweat. When relative humidity is on the rise, it curtails evaporation, thereby reducing the heat elimination from the body and causing the feeling of being excessively hot. Heat-related complications, like dehydration, can manifest if the body's heat gain exceeds its dissipation capacity.
Humidity
In Port Isabel, the average relative humidity in September is 74%.Rainfall
The month with the most rainfall is September, when the rain falls for 19.8 days and typically aggregates up to 4.13" (105mm) of precipitation.Ocean temperature
In September, the average ocean temperature is 84.6°F (29.2°C).Note: For any water activity, temperatures between 77°F (25°C) and 84.2°F (29°C) are deemed excellent and extremely satisfying for enduring periods.
Daylight
In Port Isabel, the average length of the day in September is 12h and 18min.On the first day of September, sunrise is at 7:09 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 7:16 pm CDT.
Sunshine
In Port Isabel, the average sunshine in September is 9h.UV index
The months with the highest UV index are April through September, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for average individuals.Note: In September, the maximum UV index of 7 transforms into these recommendations:
Fend off overexposure. Sun protection is vital. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit. Be wary! Reflections from sand and water make UV radiation more intense.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September in Port Isabel?
What is the wettest month?
How many days does it rain in September?
How warm is the water in September?
How many hours of daylight does Port Isabel have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Port Isabel have in September?
What is the month with the highest UV index?
What is the UV index intensity in September?
Average temperature in September
Port Isabel, TX
- Average high temperature in September: 86.2°F
The warmest month (with the highest average high temperature) is August (88°F).
The month with the lowest average high temperature is January (67.1°F).
- Average low temperature in September: 80.4°F
The month with the highest average low temperature is August (82°F).
The coldest month (with the lowest average low temperature) is January (59.5°F).
Average pressure in September
Port Isabel, TX
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are May and June (29.88"Hg).
Average wind speed in September
Port Isabel, TX
- Average wind speed in September: 10.9mph
The windiest month (with the highest average wind speed) is April (14.2mph).
The calmest month (with the lowest average wind speed) is September (10.9mph).
Average humidity in September
Port Isabel, TX
- Average humidity in September: 74%
The month with the highest relative humidity is May (80%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Port Isabel, TX
- Average rainfall in September: 4.13"
The wettest month (with the highest rainfall) is September (4.13").
The driest month (with the least rainfall) is April (0.51").
Average rainfall days in September
Port Isabel, TX
- Average rainfall days in September: 19.8 days
The month with the highest number of rainy days is September (19.8 days).
The month with the least rainy days is March (8.2 days).
Average sea temperature in September
Port Isabel, TX
- Average sea temperature in September: 84.6°F
The best month for swimming (with the highest average sea temperature) is August (85.1°F).
The coldest month (with the lowest average sea temperature) is February (66.7°F).
Average daylight in September /
Average sunshine in September
Port Isabel, TX
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 42min).
The month with the shortest days is December (Average daylight: 10h and 30min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).
Average sunshine days in September
Port Isabel, TX
- Average sunshine days in September: 7.2 days
The month with the most sunshine days is March (20.7 days).
The month with the least sunshine days is September (7.2 days).
Average UV index in September
Port Isabel, TX
- Average UV index in September: 7
The months with the highest UV index are April, May, June, July, August and September (UV index 7).
The months with the lowest UV index are January, February and December (UV index 5).
Average cloud cover in September
Port Isabel, TX
- Average cloud cover in September: 29
The month with the most cloud cover is December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in September
Port Isabel, TX
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Port Isabel, Texas, USA
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