Average Weather in September in South Padre Island Texas, United States
In South Padre Island, the month of September is characterized by gradually falling daily high temperatures, with daily highs decreasing by 4°F, from 89°F to 86°F over the course of the month, and rarely exceeding 93°F or dropping below 81°F.
Daily low temperatures decrease by 4°F, from 78°F to 74°F, rarely falling below 68°F or exceeding 81°F.
For reference, on August 4, the hottest day of the year, temperatures in South Padre Island typically range from 79°F to 90°F, while on January 5, the coldest day of the year, they range from 56°F to 68°F.
Average High and Low Temperature in September
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on September. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in September
The month of September in South Padre Island experiences rapidly decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 58% to 44%.
The clearest day of the month is September 30, with clear, mostly clear, or partly cloudy conditions 56% of the time.
For reference, on August 22, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 60%, while on June 3, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 75%.
Cloud Cover in September
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In South Padre Island, the chance of a wet day over the course of September is essentially constant, remaining around 35% throughout.
For reference, the year's highest daily chance of a wet day is 39% on September 15, and its lowest chance is 9% on February 21.
Probability of Precipitation in September
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during September in South Padre Island is gradually increasing, starting the month at 3.3 inches, when it rarely exceeds 6.4 inches or falls below 0.7 inches, and ending the month at 3.6 inches, when it rarely exceeds 7.1 inches or falls below 1.0 inches.
The highest average 31-day accumulation is 4.1 inches on September 18.
Average Monthly Rainfall in September
Over the course of September in South Padre Island, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 44 minutes, implying an average daily decrease of 1 minute, 31 seconds, and weekly decrease of 10 minutes, 35 seconds.
The shortest day of the month is September 30, with 11 hours, 55 minutes of daylight and the longest day is September 1, with 12 hours, 39 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in South Padre Island is 7:08 AM on September 1 and the latest sunrise is 12 minutes later at 7:20 AM on September 30.
The latest sunset is 7:47 PM on September 1 and the earliest sunset is 32 minutes earlier at 7:15 PM on September 30.
Daylight saving time is observed in South Padre Island during 2017, but it neither starts nor ends during September, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 6:37 AM and sets 13 hours, 47 minutes later, at 8:23 PM, while on December 21, the shortest day of the year, it rises at 7:11 AM and sets 10 hours, 30 minutes later, at 5:42 PM.
Sunrise & Sunset with Twilight in September
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The chance that a given day will be muggy in South Padre Island is rapidly decreasing during September, falling from 100% to 85% over the course of the month.
For reference, on July 16, the muggiest day of the year, there are muggy conditions 100% of the time, while on January 24, the leasy muggy day of the year, there are muggy conditions 20% of the time.
Humidity Comfort Levels in September
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in South Padre Island is gradually increasing during September, increasing from 5.7 miles per hour to 6.2 miles per hour over the course of the month.
For reference, on April 26, the windiest day of the year, the daily average wind speed is 7.4 miles per hour, while on September 1, the calmest day of the year, the daily average wind speed is 5.7 miles per hour.
The lowest daily average wind speed during September is 5.7 miles per hour on September 1.
Average Wind Speed in September
Wind Direction in September
South Padre Island is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in South Padre Island is essentially constant during September, remaining within 1°F of 83°F throughout.
The highest average surface water temperature during September is 84°F on September 8.
Average Water Temperature in September
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy in South Padre Island is essentially constant during September, remaining within 0.1 kWh of 5.1 kWh throughout.
Average Daily Incident Shortwave Solar Energy in September
For the purposes of this report, the geographical coordinates of South Padre Island are 26.104 deg latitude, -97.165 deg longitude, and 0 ft elevation.
The topography within 2 miles of South Padre Island is essentially flat, with a maximum elevation change of 10 feet and an average elevation above sea level of 0 feet. Within 10 miles is also essentially flat (30 feet). Within 50 miles is essentially flat (131 feet).
The area within 2 miles of South Padre Island is covered by water (84%) and bare soil (10%), within 10 miles by water (77%) and bare soil (17%), and within 50 miles by water (61%) and cropland (19%).
This report illustrates the typical weather in South Padre Island year round, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in South Padre Island.
For each station, the records are corrected for the elevation difference between that station and South Padre Island according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at South Padre Island is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between South Padre Island and a given station.
The stations contributing to this reconstruction are: Port Isabel, Port Isabel-Cameron County Airport (69%, 19 kilometers, west) and Brownsville-South Padre Island International Airport (31%, 33 kilometers, southwest).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.