Average Weather in April in Houston Texas, United States
Daily high temperatures increase by 6°F, from 76°F to 82°F, rarely falling below 68°F or exceeding 88°F.
Daily low temperatures increase by 7°F, from 60°F to 67°F, rarely falling below 48°F or exceeding 74°F.
For reference, on August 5, the hottest day of the year, temperatures in Houston typically range from 77°F to 95°F, while on January 5, the coldest day of the year, they range from 47°F to 63°F.
Average High and Low Temperature in April
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on April. 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 April
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 April in Houston experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 38% throughout the month.
The clearest day of the month is April 25, with clear, mostly clear, or partly cloudy conditions 63% of the time.
For reference, on August 19, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 49%, while on October 9, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 69%.
Cloud Cover Categories in April
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 Houston, the chance of a wet day over the course of April is increasing, starting the month at 22% and ending it at 27%.
For reference, the year's highest daily chance of a wet day is 40% on June 23, and its lowest chance is 21% on April 14.
Probability of Precipitation in April
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 April in Houston is increasing, starting the month at 3.0 inches, when it rarely exceeds 6.1 inches or falls below 0.5 inches, and ending the month at 3.7 inches, when it rarely exceeds 6.9 inches or falls below 0.8 inches.
Average Monthly Rainfall in April
Over the course of April in Houston, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 49 minutes, implying an average daily increase of 1 minute, 41 seconds, and weekly increase of 11 minutes, 46 seconds.
The shortest day of the month is April 1, with 12 hours, 30 minutes of daylight and the longest day is April 30, with 13 hours, 19 minutes of daylight.
Hours of Daylight and Twilight in April
The latest sunrise of the month in Houston is 7:10 AM on April 1 and the earliest sunrise is 31 minutes earlier at 6:39 AM on April 30.
The earliest sunset is 7:40 PM on April 1 and the latest sunset is 18 minutes later at 7:58 PM on April 30.
Daylight saving time is observed in Houston during 2020, but it neither starts nor ends during April, so the entire month is in daylight saving time.
For reference, on June 20, the longest day of the year, the Sun rises at 6:21 AM and sets 14 hours, 4 minutes later, at 8:25 PM, while on December 21, the shortest day of the year, it rises at 7:12 AM and sets 10 hours, 14 minutes later, at 5:26 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in April
The figure below presents a compact representation of key lunar data for April 2020. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in April
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 Houston is very rapidly increasing during April, rising from 26% to 53% over the course of the month.
For reference, on July 20, the muggiest day of the year, there are muggy conditions 98% of the time, while on January 29, the least muggy day of the year, there are muggy conditions 6% of the time.
Humidity Comfort Levels in April
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 Houston is essentially constant during April, remaining within 0.2 miles per hour of 9.2 miles per hour throughout.
For reference, on April 2, the windiest day of the year, the daily average wind speed is 9.4 miles per hour, while on August 15, the calmest day of the year, the daily average wind speed is 6.2 miles per hour.
The highest daily average wind speed during April is 9.4 miles per hour on April 2.
Average Wind Speed in April
The hourly average wind direction in Houston throughout April is predominantly from the south, with a peak proportion of 59% on April 30.
Wind Direction in April
Houston 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 Houston is increasing during April, rising by 6°F, from 67°F to 74°F, over the course of the month.
Average Water Temperature in April
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).
The growing season in Houston typically lasts for 12 months (351 days), from around January 18 to around January 3, rarely starting after February 26, or ending before December 4.
The month of April in Houston is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in April
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
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 Houston are rapidly increasing during April, increasing by 587°F, from 925°F to 1,512°F, over the course of the month.
Growing Degree Days in April
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 Houston is gradually increasing during April, rising by 0.5 kWh, from 5.8 kWh to 6.3 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in April
For the purposes of this report, the geographical coordinates of Houston are 29.763 deg latitude, -95.363 deg longitude, and 36 ft elevation.
The topography within 2 miles of Houston is essentially flat, with a maximum elevation change of 56 feet and an average elevation above sea level of 43 feet. Within 10 miles is also essentially flat (95 feet). Within 50 miles is essentially flat (433 feet).
The area within 2 miles of Houston is covered by artificial surfaces (100%), within 10 miles by artificial surfaces (94%), and within 50 miles by cropland (40%) and artificial surfaces (22%).
This report illustrates the typical weather in Houston, 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 Houston.
For each station, the records are corrected for the elevation difference between that station and Houston 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 Houston is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Houston and a given station.
The stations contributing to this reconstruction are: Houston Dunn Helistop (84%, 5.5 kilometers, south) and George Bush Intercontinental Airport (16%, 24 kilometers, north).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , 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 airports 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.