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Average Weather in Delmar Delaware, United States

In Delmar, the summers are warm and muggy, the winters are very cold and windy, and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 27°F to 88°F and is rarely below 13°F or above 96°F.

Climate Summary

coldcoolwarmhotwarmcoolcoldJanFebMarAprMayJunJulAugSepOctNovDec64%64%49%49%clearovercastprecipitation: 3.8 inprecipitation: 3.8 in2.9 in2.9 inmuggy: 72%muggy: 72%0%0%drydrytourism score: 6.3tourism score: 6.30.50.5
Click on each chart for more information.

Based on the tourism score, the best times of year to visit Delmar for warm-weather activities are from late May to late June and from mid August to early October.

Temperature

The hot season lasts for 3.6 months, from May 30 to September 16, with an average daily high temperature above 79°F. The hottest day of the year is July 21, with an average high of 88°F and low of 69°F.

The cold season lasts for 3.0 months, from December 4 to March 5, with an average daily high temperature below 53°F. The coldest day of the year is January 30, with an average low of 27°F and high of 44°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

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

Average Hourly Temperature in DelmarJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMvery coldvery coldcoldcoldcoolcoolcomfortablewarmhotfreezing
The average hourly temperature, color coded into bands: 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 shaded overlays indicate night and civil twilight.

Bagratashen, Armenia (5,780 miles away) and Darzāb, Afghanistan (6,729 miles) are the far-away foreign places with temperatures most similar to Delmar (view comparison).

Clouds

In Delmar, 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 Delmar begins around July 15 and lasts for 4.2 months, ending around November 22. 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 22 and lasts for 7.8 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

Cloud Cover Categories in DelmarclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Oct 1264%Oct 1264%Jan 549%Jan 549%Jul 1556%Jul 1556%Nov 2256%Nov 2256%clearmostly clearpartly cloudyovercast
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Delmar varies throughout the year.

The wetter season lasts 4.8 months, from April 1 to August 27, with a greater than 30% 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 April 1. 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

Daily Chance of Precipitation in DelmarwetdrydryJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Aug 638%Aug 638%Oct 2021%Oct 2021%Jan 126%Jan 126%Apr 130%Apr 130%rainsnow
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

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. Delmar experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Delmar. 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 January 30, with an average total accumulation of 2.4 inches.

Average Monthly Rainfall

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

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. Delmar experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 3.8 months, from November 25 to March 19, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 26, with an average total liquid-equivalent accumulation of 0.4 inches.

The snowless period of the year lasts for 8.2 months, from March 19 to November 25. The least snow falls around July 18, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

Average Liquid-Equivalent Monthly Snowfall in DelmarsnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.5 in1.0 in1.5 in2.0 in2.5 in3.0 in3.5 in4.0 inJan 260.4 inJan 260.4 inJul 180.0 inJul 180.0 inNov 250.1 inNov 250.1 inMar 190.1 inMar 190.1 in
The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Sun

The length of the day in Delmar varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 29 minutes of daylight; the longest day is June 21, with 14 hours, 51 minutes of daylight.

Hours of Daylight and Twilight

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise is at 5:37 AM on June 13, and the latest sunrise is 1 hour, 55 minutes later at 7:32 AM on November 4. The earliest sunset is at 4:41 PM on December 7, and the latest sunset is 3 hours, 49 minutes later at 8:30 PM on June 28.

Daylight saving time (DST) is observed in Delmar 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

Sunrise & Sunset with Twilight and Daylight Saving Time in DelmarJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 135:37 AMJun 135:37 AM8:30 PMJun 288:30 PMJun 28Dec 74:41 PMDec 74:41 PM7:32 AMNov 47:32 AMNov 4Mar 12DSTMar 12DSTDSTNov 5DSTNov 5daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of the year 2017. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Humidity

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.

Delmar experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.4 months, from May 20 to October 1, during which time the comfort level is muggy, oppressive, or miserable at least 18% of the time. The muggiest day of the year is August 2, with muggy conditions 72% of the time.

The least muggy day of the year is February 14, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

Humidity Comfort Levels in DelmarmuggyJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Feb 140%Feb 140%Aug 272%Aug 272%May 2018%May 2018%Oct 118%Oct 118%oppressiveoppressivemuggymuggydrydrymiserablemiserablecomfortablecomfortable
The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.

Wind

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 Delmar experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.0 months, from October 12 to May 14, with average wind speeds of more than 10.2 miles per hour. The windiest day of the year is February 26, with an average hourly wind speed of 12.4 miles per hour.

The calmer time of year lasts for 5.0 months, from May 14 to October 12. The calmest day of the year is August 13, with an average hourly wind speed of 7.9 miles per hour.

Average Wind Speed

Average Wind Speed in DelmarwindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mph18 mph20 mphFeb 2612.4 mphFeb 2612.4 mphAug 137.9 mphAug 137.9 mphOct 1210.2 mphOct 1210.2 mphMay 1410.2 mphMay 1410.2 mph
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The predominant average hourly wind direction in Delmar varies throughout the year.

The wind is most often from the north for 2.3 months, from January 22 to March 30 and for 1.5 months, from October 4 to November 20, with a peak percentage of 35% on January 29. The wind is most often from the south for 6.2 months, from March 30 to October 4, with a peak percentage of 41% on July 28. The wind is most often from the west for 2.1 months, from November 20 to January 22, with a peak percentage of 34% on January 1.

Wind Direction

Wind Direction in DelmarWNSNWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westsouthnortheast
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Water Temperature

Delmar 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 19 to October 3, with an average temperature above 69°F. The day of the year with the warmest water is August 7, with an average temperature of 76°F.

The time of year with cooler water lasts for 3.6 months, from December 21 to April 9, with an average temperature below 47°F. The day of the year with the coolest water is February 12, with an average temperature of 40°F.

Average Water Temperature

The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Best Time of Year to Visit

To characterize how pleasant the weather is in Delmar 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 Delmar for general outdoor tourist activities are from late May to late June and from mid August to early October, with a peak score in the first week of September.

Tourism Score

Tourism Score in Delmarbest timeJanFebMarAprMayJunJulAugSepOctNovDec02468106.36.30.50.55.75.75.25.2 precipitationprecipitationcloudscloudstemperaturetemperaturetourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

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 Delmar for hot-weather activities is from mid June to early September, with a peak score in the second week of August.

Beach/Pool Score

Beach/Pool Score in Delmarbest timeJanFebMarAprMayJunJulAugSepOctNovDec02468105.85.80.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturebeach/pool score
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Methodology

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.

Growing Season

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 Delmar typically lasts for 6.5 months (198 days), from around April 11 to around October 26, rarely starting before March 24 or after April 30, and rarely ending before October 9 or after November 12.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Delmargrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Apr 1150%Apr 1150%Oct 2650%Oct 2690%Apr 3090%Apr 3090%Oct 990%Oct 910%Mar 2410%Mar 2410%Nov 1210%Nov 120%Dec 160%Dec 16Jul 31100%Jul 31100%freezingvery coldcomfortablewarmhotcoldcoolfrigid
The percentage of time spent in various temperature bands: 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 black line is the percentage chance that a given day is 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.

Based on growing degree days alone, the first spring blooms in Delmar should appear around March 10, only rarely appearing before February 21 or after March 29.

Growing Degree Days

Growing Degree Days in DelmarJanFebMarAprMayJunJulAugSepOctNovDec0°F500°F1,000°F1,500°F2,000°F2,500°F3,000°F3,500°F4,000°FMar 1085°FMar 1085°FJun 4900°FJun 4900°FJul 111,800°FJul 111,800°FDec 314,144°FDec 314,144°F
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

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 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 7.0 kWh.

The darker period of the year lasts for 3.1 months, from November 7 to February 9, with an average daily incident shortwave energy per square meter below 3.0 kWh. The darkest day of the year is December 20, with an average of 2.1 kWh.

Average Daily Incident Shortwave Solar Energy

The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Delmar are 38.457 deg latitude, -75.577 deg longitude, and 43 ft elevation.

The topography within 2 miles of Delmar is essentially flat, with a maximum elevation change of 30 feet and an average elevation above sea level of 44 feet. Within 10 miles is essentially flat (125 feet). Within 50 miles also contains only modest variations in elevation (138 feet).

The area within 2 miles of Delmar is covered by cropland (61%), artificial surfaces (25%), and trees (13%), within 10 miles by cropland (57%) and trees (32%), and within 50 miles by water (47%) and cropland (26%).

Data Sources

This report illustrates the typical weather in Delmar, 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 Delmar.

For each station, the records are corrected for the elevation difference between that station and Delmar 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 Delmar is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Delmar and a given station.

The stations contributing to this reconstruction are: Salisbury–Ocean City–Wicomico Regional Airport (67%, 14 kilometers, southeast); Sussex County Airport (19%, 32 kilometers, northeast); and Cambridge-Dorchester Airport (14%, 41 kilometers, west).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports 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.

Disclaimer

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.