Average Weather in September in Baytown Texas, United States
Daily high temperatures decrease by 6°F, from 90°F to 85°F, rarely falling below 78°F or exceeding 95°F.
Daily low temperatures decrease by 7°F, from 76°F to 69°F, rarely falling below 59°F or exceeding 79°F.
For reference, on August 5, the hottest day of the year, temperatures in Baytown typically range from 77°F to 92°F, while on January 6, the coldest day of the year, they range from 46°F to 62°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 Baytown experiences rapidly decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 47% to 34%.
The clearest day of the month is September 30, with clear, mostly clear, or partly cloudy conditions 66% of the time.
For reference, on August 20, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 51%, while on October 26, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 69%.
Cloud Cover Categories in September
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Baytown, the chance of a wet day over the course of September is very rapidly decreasing, starting the month at 39% and ending it at 27%.
For reference, the year's highest daily chance of a wet day is 40% on June 24, and its lowest chance is 22% on April 1.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Baytown is gradually decreasing, starting the month at 4.4 inches, when it rarely exceeds 9.4 inches or falls below 1.2 inches, and ending the month at 4.2 inches, when it rarely exceeds 7.8 inches or falls below 1.2 inches.
Average Monthly Rainfall in September
Over the course of September in Baytown, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 51 minutes, implying an average daily decrease of 1 minute, 46 seconds, and weekly decrease of 12 minutes, 20 seconds.
The shortest day of the month is September 30, with 11 hours, 54 minutes of daylight and the longest day is September 1, with 12 hours, 45 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Baytown is 6:57 AM on September 1 and the latest sunrise is 16 minutes later at 7:12 AM on September 30.
The latest sunset is 7:42 PM on September 1 and the earliest sunset is 36 minutes earlier at 7:06 PM on September 30.
Daylight saving time is observed in Baytown during 2018, 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 6:20 AM and sets 14 hours, 3 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, 14 minutes later, at 5:25 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in Baytown is very rapidly decreasing during September, falling from 95% to 62% over the course of the month.
For reference, on July 20, the muggiest day of the year, there are muggy conditions 99% of the time, while on January 29, the least muggy day of the year, there are muggy conditions 5% of the time.
Humidity Comfort Levels in September
The average hourly wind speed in Baytown is increasing during September, increasing from 6.8 miles per hour to 7.8 miles per hour over the course of the month.
For reference, on April 11, the windiest day of the year, the daily average wind speed is 9.8 miles per hour, while on August 15, the calmest day of the year, the daily average wind speed is 6.6 miles per hour.
Average Wind Speed in September
Wind Direction in September
Baytown 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 Baytown is decreasing during September, falling by 5°F, from 85°F to 81°F, over the course of the month.
Average Water Temperature in September
The growing season in Baytown typically lasts for 11 months (341 days), from around January 25 to around January 1, rarely starting after March 6, or ending before December 5.
The month of September in Baytown is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in September
The average accumulated growing degree days in Baytown are rapidly increasing during September, increasing by 832°F, from 5,148°F to 5,980°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Baytown is essentially constant during September, remaining within 0.1 kWh of 5.2 kWh throughout.
Average Daily Incident Shortwave Solar Energy in September
For the purposes of this report, the geographical coordinates of Baytown are 29.736 deg latitude, -94.977 deg longitude, and 20 ft elevation.
The topography within 2 miles of Baytown is essentially flat, with a maximum elevation change of 36 feet and an average elevation above sea level of 20 feet. Within 10 miles is also essentially flat (79 feet). Within 50 miles is essentially flat (289 feet).
The area within 2 miles of Baytown is covered by artificial surfaces (90%), within 10 miles by artificial surfaces (43%) and water (26%), and within 50 miles by cropland (28%) and herbaceous vegetation (24%).
This report illustrates the typical weather in Baytown 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Baytown.
For each station, the records are corrected for the elevation difference between that station and Baytown 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 Baytown is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Baytown and a given station.
The stations contributing to this reconstruction are: Ellington Field (57%, 23 kilometers, southwest); George Bush Intercontinental Airport (19%, 46 kilometers, northwest); Scholes Field (16%, 53 kilometers, south); and Beaumont Municipal Airport (8%, 82 kilometers, northeast).
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.
Time zones for aiports and weather stations are provided by AskGeo.com .