Average Weather in Rehoboth Beach Delaware, United States
In Rehoboth Beach, the summers are warm and muggy; the winters are very cold, wet, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 29°F to 84°F and is rarely below 17°F or above 90°F.
Based on the tourism score, the best times of year to visit Rehoboth Beach for warm-weather activities are from early June to early July and from mid August to early October.
The warm season lasts for 3.5 months, from June 3 to September 18, with an average daily high temperature above 76°F. The hottest day of the year is July 21, with an average high of 84°F and low of 71°F.
The cold season lasts for 3.2 months, from December 6 to March 13, with an average daily high temperature below 51°F. The coldest day of the year is January 31, with an average low of 29°F and high of 43°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
Gedzhukh, Russia (5,815 miles away); Ikedachō, Japan (7,089 miles); and Uenohara, Japan (6,863 miles) are the far-away foreign places with temperatures most similar to Rehoboth Beach (view comparison).
In Rehoboth Beach, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.
The clearer part of the year in Rehoboth Beach begins around July 15 and lasts for 4.0 months, ending around November 14. On October 12, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 64% of the time, and overcast or mostly cloudy 36% of the time.
The cloudier part of the year begins around November 14 and lasts for 8.0 months, ending around July 15. On January 5, the cloudiest day of the year, the sky is overcast or mostly cloudy 51% of the time, and clear, mostly clear, or partly cloudy 49% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Rehoboth Beach varies throughout the year.
The wetter season lasts 4.9 months, from March 31 to August 27, with a greater than 29% chance of a given day being a wet day. The chance of a wet day peaks at 38% on August 6.
The drier season lasts 7.1 months, from August 27 to March 31. The smallest chance of a wet day is 21% on October 20.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 38% on August 6.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Rehoboth Beach experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Rehoboth Beach. The most rain falls during the 31 days centered around August 12, with an average total accumulation of 3.8 inches.
The least rain falls around February 3, with an average total accumulation of 2.6 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Rehoboth Beach experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 2.9 months, from December 16 to March 13, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around February 10, with an average total liquid-equivalent accumulation of 0.3 inches.
The snowless period of the year lasts for 9.1 months, from March 13 to December 16. The least snow falls around July 25, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Rehoboth Beach varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 27 minutes of daylight; the longest day is June 21, with 14 hours, 53 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:34 AM on June 13, and the latest sunrise is 1 hour, 56 minutes later at 7:30 AM on November 4. The earliest sunset is at 4:38 PM on December 7, and the latest sunset is 3 hours, 51 minutes later at 8:29 PM on June 27.
Daylight saving time (DST) is observed in Rehoboth Beach during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
Rehoboth Beach experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 4.2 months, from May 28 to October 2, during which time the comfort level is muggy, oppressive, or miserable at least 19% of the time. The muggiest day of the year is August 2, with muggy conditions 75% of the time.
The least muggy day of the year is February 23, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
The average hourly wind speed in Rehoboth Beach experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 7.1 months, from September 30 to May 3, with average wind speeds of more than 11.8 miles per hour. The windiest day of the year is January 13, with an average hourly wind speed of 14.7 miles per hour.
The calmer time of year lasts for 4.9 months, from May 3 to September 30. The calmest day of the year is July 26, with an average hourly wind speed of 8.9 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Rehoboth Beach varies throughout the year.
The wind is most often from the north for 1.2 months, from February 22 to March 28 and for 1.1 months, from October 11 to November 13, with a peak percentage of 32% on March 10. The wind is most often from the south for 6.5 months, from March 28 to October 11, with a peak percentage of 42% on July 14. The wind is most often from the west for 3.3 months, from November 13 to February 22, with a peak percentage of 37% on January 1.
Rehoboth 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 water temperature experiences significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 3.5 months, from June 20 to October 4, with an average temperature above 68°F. The day of the year with the warmest water is August 8, with an average temperature of 75°F.
The time of year with cooler water lasts for 3.6 months, from December 22 to April 9, with an average temperature below 47°F. The day of the year with the coolest water is February 14, with an average temperature of 39°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in Rehoboth Beach throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Rehoboth Beach for general outdoor tourist activities are from early June to early July and from mid August to early October, with a peak score in the first week of September.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Rehoboth Beach for hot-weather activities is from late June to early September, with a peak score in the third week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in Rehoboth 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 14, and rarely ending before October 31 or after December 5.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Rehoboth Beach should appear around March 28, only rarely appearing before March 11 or after April 15.
Growing Degree Days
The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.
The brighter period of the year lasts for 3.8 months, from April 24 to August 19, with an average daily incident shortwave energy per square meter above 6.0 kWh. The brightest day of the year is June 23, with an average of 6.9 kWh.
The darker period of the year lasts for 3.1 months, from November 6 to February 10, with an average daily incident shortwave energy per square meter below 3.0 kWh. The darkest day of the year is December 23, with an average of 2.0 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Rehoboth Beach are 38.721 deg latitude, -75.076 deg longitude, and 0 ft elevation.
The topography within 2 miles of Rehoboth Beach is essentially flat, with a maximum elevation change of 26 feet and an average elevation above sea level of 5 feet. Within 10 miles is also essentially flat (66 feet). Within 50 miles is essentially flat (128 feet).
The area within 2 miles of Rehoboth Beach is covered by water (58%) and artificial surfaces (34%), within 10 miles by water (69%) and cropland (14%), and within 50 miles by water (54%) and cropland (21%).
This report illustrates the typical weather in Rehoboth 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 Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Rehoboth Beach.
For each station, the records are corrected for the elevation difference between that station and Rehoboth 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 Rehoboth Beach is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Rehoboth Beach and a given station.
The stations contributing to this reconstruction are: Sussex County Airport (50%, 25 kilometers, west); Cape May County Airport (30%, 35 kilometers, northeast); and Ocean City Municipal Airport (20%, 46 kilometers, south).
Time zones for aiports and weather stations are provided by AskGeo.com .