Spring Weather in Bethany Beach Delaware, United StatesDaily high temperatures increase by 25°F, from 49°F to 74°F, rarely falling below 37°F or exceeding 83°F. Daily low temperatures increase by 26°F, from 34°F to 60°F, rarely falling below 23°F or exceeding 68°F. For reference, on July 21, the hottest day of the year, temperatures in Bethany Beach typically range from 71°F to 83°F, while on January 31, the coldest day of the year, they range from 29°F to 43°F. The figure below shows you a compact characterization of the hourly average spring temperatures. 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. CloudsThe spring in Bethany Beach experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 48% throughout the season. The clearest day of the spring is May 1, with clear, mostly clear, or partly cloudy conditions 54% of the time. For reference, on January 5, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 51%, while on October 12, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 64%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Bethany Beach, the chance of a wet day over the course of the spring is gradually increasing, starting the season at 29% and ending it at 32%. For reference, the year's highest daily chance of a wet day is 39% on August 7, and its lowest chance is 21% on October 20. Over the course of the spring in Bethany Beach, the chance of a day with only rain increases from 25% to 32%, the chance of a day with mixed snow and rain decreases from 3% to 0%, and the chance of a day with only snow remains an essentially constant 1% throughout. RainfallTo show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day rainfall during the spring in Bethany Beach is essentially constant, remaining about 3.4 inches throughout, and rarely exceeding 6.6 inches or falling below 1.0 inches. The highest average 31-day accumulation is 3.8 inches on March 29. SnowfallAs with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day snowfall during the spring in Bethany Beach is decreasing, starting the season at 1.8 inches, when it rarely exceeds 6.9 inches or falls below -0.0 inches, and ending the season at -0.0 inches, when it rarely exceeds 0.0 inches or falls below -0.0 inches. SunOver the course of the spring in Bethany Beach, the length of the day is very rapidly increasing. From the start to the end of the season, the length of the day increases by 3 hours, 19 minutes, implying an average daily increase of 2 minutes, 11 seconds, and weekly increase of 15 minutes, 16 seconds. The shortest day of the spring is March 1, with 11 hours, 22 minutes of daylight and the longest day is May 31, with 14 hours, 40 minutes of daylight. The latest sunrise of the spring in Bethany Beach is 7:20 AM on March 9 and the earliest sunrise is 1 hour, 42 minutes earlier at 5:38 AM on May 31. The earliest sunset is 5:53 PM on March 1 and the latest sunset is 2 hours, 25 minutes later at 8:18 PM on May 31. Daylight saving time (DST) starts at 3:00 AM on March 9, 2025, shifting sunrise and sunset to be an hour later. For reference, on June 21, the longest day of the year, the Sun rises at 5:36 AM and sets 14 hours, 52 minutes later, at 8:27 PM, while on December 21, the shortest day of the year, it rises at 7:14 AM and sets 9 hours, 28 minutes later, at 4:42 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. MoonThe figure below presents a compact representation of key lunar data for the spring of 2025. 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. HumidityWe 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 Bethany Beach is very rapidly increasing during the spring, rising from 0% to 25% over the course of the season. For reference, on August 2, the muggiest day of the year, there are muggy conditions 78% of the time, while on January 9, the least muggy day of the year, there are muggy conditions 0% of the time. WindThis 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 Bethany Beach is rapidly decreasing during the spring, decreasing from 14.4 miles per hour to 10.5 miles per hour over the course of the season. For reference, on January 13, the windiest day of the year, the daily average wind speed is 15.0 miles per hour, while on July 26, the calmest day of the year, the daily average wind speed is 9.1 miles per hour. The wind direction in Bethany Beach during the spring is predominantly out of the north from March 1 to March 28 and the south from March 28 to May 31. Water TemperatureBethany Beach 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 Bethany Beach is very rapidly increasing during the spring, rising by 21°F, from 41°F to 62°F, over the course of the season. Growing SeasonDefinitions 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 Bethany Beach typically lasts for 7.7 months (235 days), from around March 27 to around November 17, rarely starting before March 10 or after April 12, and rarely ending before November 1 or after December 4. During the spring in Bethany Beach, the chance that a given day is within the growing season is very rapidly increasing rising from 2% to 100% over the course of the 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 Bethany Beach are rapidly increasing during the spring, increasing by 606°F, from 37°F to 643°F, over the course of the season. Solar EnergyThis 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 Bethany Beach is very rapidly increasing during the spring, rising by 3.0 kWh, from 3.8 kWh to 6.7 kWh, over the course of the season. TopographyFor the purposes of this report, the geographical coordinates of Bethany Beach are 38.540 deg latitude, -75.055 deg longitude, and 7 ft elevation. The topography within 2 miles of Bethany Beach is essentially flat, with a maximum elevation change of 13 feet and an average elevation above sea level of 2 feet. Within 10 miles is also essentially flat (39 feet). Within 50 miles is essentially flat (128 feet). The area within 2 miles of Bethany Beach is covered by water (48%), artificial surfaces (31%), and herbaceous vegetation (10%), within 10 miles by water (66%) and cropland (16%), and within 50 miles by water (61%) and cropland (19%). Data SourcesThis report illustrates the typical weather in Bethany Beach, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointThere are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Bethany Beach. For each station, the records are corrected for the elevation difference between that station and Bethany Beach 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 Bethany Beach is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Bethany Beach and a given station. The stations contributing to this reconstruction are:
To get a sense of how much these sources agree with each other, you can view a comparison of Bethany Beach and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data. Other DataAll 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 © OpenStreetMap contributors. DisclaimerThe 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. Please review our full terms contained on our Terms of Service page. |