Average Weather in March in Port Isabel Texas, United States
Daily high temperatures increase by 5°F, from 73°F to 77°F, rarely falling below 63°F or exceeding 83°F.
Daily low temperatures increase by 6°F, from 60°F to 66°F, rarely falling below 48°F or exceeding 73°F.
For reference, on July 28, the hottest day of the year, temperatures in Port Isabel typically range from 79°F to 91°F, while on January 5, the coldest day of the year, they range from 54°F to 68°F.
Average High and Low Temperature in March
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on March. 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 March
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The month of March in Port Isabel experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 39% throughout the month.
The clearest day of the month is March 15, with clear, mostly clear, or partly cloudy conditions 62% 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 Categories in March
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Port Isabel, the chance of a wet day over the course of March is essentially constant, remaining around 11% throughout.
For reference, the year's highest daily chance of a wet day is 39% on September 15, and its lowest chance is 8% on February 21.
Probability of Precipitation in March
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 March in Port Isabel is essentially constant, remaining about 1.0 inches throughout, and rarely exceeding 3.1 inches.
Average Monthly Rainfall in March
Over the course of March in Port Isabel, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 46 minutes, implying an average daily increase of 1 minute, 32 seconds, and weekly increase of 10 minutes, 46 seconds.
The shortest day of the month is March 1, with 11 hours, 38 minutes of daylight and the longest day is March 31, with 12 hours, 24 minutes of daylight.
Hours of Daylight and Twilight in March
The earliest sunrise of the month in Port Isabel is 6:43 AM on March 10 and the latest sunrise is 59 minutes later at 7:42 AM on March 11.
The earliest sunset is 6:30 PM on March 1 and the latest sunset is 1 hour, 15 minutes later at 7:45 PM on March 31.
Daylight saving time (DST) starts at 3:00 AM on March 11, 2018, shifting sunrise and sunset to be an hour later.
For reference, on June 21, the longest day of the year, the Sun rises at 6:37 AM and sets 13 hours, 46 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 and Daylight Saving Time in March
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 Port Isabel is very rapidly increasing during March, rising from 35% to 57% 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 least muggy day of the year, there are muggy conditions 22% of the time.
Humidity Comfort Levels in March
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Port Isabel is essentially constant during March, remaining within 0.1 miles per hour of 13.3 miles per hour throughout.
For reference, on April 26, the windiest day of the year, the daily average wind speed is 13.5 miles per hour, while on September 1, the calmest day of the year, the daily average wind speed is 10.3 miles per hour.
Average Wind Speed in March
Wind Direction in March
Port Isabel 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 Port Isabel is gradually increasing during March, rising by 3°F, from 67°F to 69°F, over the course of the month.
Average Water Temperature in March
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
Temperatures in Port Isabel are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Time Spent in Various Temperature Bands and the Growing Season in March
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
The average accumulated growing degree days in Port Isabel are rapidly increasing during March, increasing by 529°F, from 733°F to 1,262°F, over the course of the month.
Growing Degree Days in March
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 Port Isabel is gradually increasing during March, rising by 0.9 kWh, from 5.1 kWh to 6.1 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in March
For the purposes of this report, the geographical coordinates of Port Isabel are 26.073 deg latitude, -97.209 deg longitude, and 0 ft elevation.
The topography within 2 miles of Port Isabel is essentially flat, with a maximum elevation change of 20 feet and an average elevation above sea level of 1 foot. Within 10 miles is also essentially flat (66 feet). Within 50 miles is essentially flat (135 feet).
The area within 2 miles of Port Isabel is covered by water (59%), bare soil (17%), and artificial surfaces (12%), within 10 miles by water (55%) and bare soil (24%), and within 50 miles by water (58%) and cropland (21%).
This report illustrates the typical weather in Port Isabel 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 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Port Isabel.
For each station, the records are corrected for the elevation difference between that station and Port Isabel 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 Port Isabel is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Port Isabel and a given station.
The stations contributing to this reconstruction are: South Padre Island Heliport (77%, 5.9 kilometers, east); Port Isabel, Port Isabel-Cameron County Airport (16%, 17 kilometers, northwest); and Brownsville-South Padre Island International Airport (8%, 28 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.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.