May Weather in Sam Rayburn United States

Daily high temperatures increase by 6°F, from 82°F to 87°F, rarely falling below 75°F or exceeding 93°F.

Daily low temperatures increase by 6°F, from 62°F to 68°F, rarely falling below 51°F or exceeding 74°F.

For reference, on August 10, the hottest day of the year, temperatures in Sam Rayburn typically range from 73°F to 94°F, while on January 7, the coldest day of the year, they range from 41°F to 60°F.

The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on May. 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.

Adana, Turkey (6,715 miles away); Meipu, China (7,930 miles); and Roxby Downs, Australia (9,452 miles) are the far-away foreign places with temperatures most similar to Sam Rayburn (view comparison).

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The month of May in Sam Rayburn experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 40% throughout the month. The highest chance of overcast or mostly cloudy conditions is 41% on May 14.

The clearest day of the month is May 31, with clear, mostly clear, or partly cloudy conditions 62% of the time.

For reference, on January 3, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 49%, while on October 11, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 70%.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Sam Rayburn, the chance of a wet day over the course of May is increasing, starting the month at 31% and ending it at 35%.

For reference, the year's highest daily chance of a wet day is 40% on June 21, and its lowest chance is 24% on October 10.

Rainfall

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 May in Sam Rayburn is gradually increasing, starting the month at 4.1 inches, when it rarely exceeds 7.8 inches or falls below 1.1 inches, and ending the month at 4.5 inches, when it rarely exceeds 8.5 inches or falls below 1.5 inches.

Over the course of May in Sam Rayburn, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 37 minutes, implying an average daily increase of 1 minute, 15 seconds, and weekly increase of 8 minutes, 42 seconds.

The shortest day of the month is May 1, with 13 hours, 24 minutes of daylight and the longest day is May 31, with 14 hours, 2 minutes of daylight.

The latest sunrise of the month in Sam Rayburn is 6:31 AM on May 1 and the earliest sunrise is 18 minutes earlier at 6:13 AM on May 31.

The earliest sunset is 7:55 PM on May 1 and the latest sunset is 19 minutes later at 8:14 PM on May 31.

Daylight saving time is observed in Sam Rayburn during 2024, but it neither starts nor ends during May, so the entire month is in standard time.

For reference, on June 20, the longest day of the year, the Sun rises at 6:12 AM and sets 14 hours, 10 minutes later, at 8:22 PM, while on December 21, the shortest day of the year, it rises at 7:10 AM and sets 10 hours, 8 minutes later, at 5:18 PM.

The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

The figure below presents a compact representation of key lunar data for May 2024. 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.

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 Sam Rayburn is very rapidly increasing during May, rising from 44% to 80% over the course of the month.

For reference, on July 22, the muggiest day of the year, there are muggy conditions 98% of the time, while on January 23, the least muggy day of the year, there are muggy conditions 4% of the time.

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 Sam Rayburn is gradually decreasing during May, decreasing from 4.8 miles per hour to 4.2 miles per hour over the course of the month.

For reference, on March 31, the windiest day of the year, the daily average wind speed is 5.0 miles per hour, while on July 29, the calmest day of the year, the daily average wind speed is 3.4 miles per hour.

The hourly average wind direction in Sam Rayburn throughout May is predominantly from the south, with a peak proportion of 62% on May 31.

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 Sam Rayburn typically lasts for 8.7 months (267 days), from around March 2 to around November 24, rarely starting before February 3 or after March 23, and rarely ending before November 1 or after December 18.

The month of May in Sam Rayburn is reliably fully within the growing season.

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 Sam Rayburn are rapidly increasing during May, increasing by 714°F, from 1,232°F to 1,946°F, over the course of the month.

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 Sam Rayburn is essentially constant during May, remaining within 0.1 kWh of 6.5 kWh throughout.

For the purposes of this report, the geographical coordinates of Sam Rayburn are 31.064 deg latitude, -94.036 deg longitude, and 197 ft elevation.

The topography within 2 miles of Sam Rayburn contains only modest variations in elevation, with a maximum elevation change of 325 feet and an average elevation above sea level of 216 feet. Within 10 miles contains only modest variations in elevation (495 feet). Within 50 miles also contains significant variations in elevation (587 feet).

The area within 2 miles of Sam Rayburn is covered by trees (80%) and water (19%), within 10 miles by trees (70%) and water (19%), and within 50 miles by trees (62%) and herbaceous vegetation (21%).