Delaware has a humid subtropical climate (Köppen climate classification Cfa) with warm to hot summers and mild to cold winters. Delaware lies on the eastern coast of the United States, in the middle of the North and the South. Delaware Bay and Delaware River separate it from New Jersey. Maryland in the south and west, Pennsylvania in the north, New Jersey in the northeast and east, and the Atlantic Ocean in the east and southeast, border the state. The Atlantic Ocean, the Atlantic High, and the Appalachian Mountains mainly influence the climate of the state.
Delaware, the First State, is at sea level and spans a distance of 96 miles in the north-south direction, with a width of 9 to 25 miles from north to south. The mean elevation of the state is the lowest among all the states in America. Ebright Azimuth is the highest point at an altitude of only 136 meters above sea level. The Appalachian Mountains act as a barrier to the cold winds during the winter. The topography is mostly flat except for the extreme north with hills up to 150 meters high. Many portions of the state are low and marshy, and the elevation rises steadily from below 10 meters at the coast to 25 meters in the interior. Numerous streams and estuaries flow in the Chesapeake Bay and the Delaware Bay. Southern Delaware has milder temperatures compared to the north, and consequently, a longer growing season.
Summers are warm to hot in Delaware. The coastal regions have oppressive heat due to the high degree of humidity than the interior. Nights are comfortable, but summer frequently experiences hot and humid periods. Temperatures of 90°F (32.2°C) and above occur for 15 to 30 days in the hot summer. The growing season ranges from 175 to 195 days in the year. Winters are between the extreme cold of the north and the mild temperatures of the south. Frost penetration in the soil ranges from 5" (127mm) to 10" (254mm) from north to south. Freezing temperatures occasionally occur with few nights dipping below 0°F (-17.8°C). Spring and fall are generally mild, with a significant degree of changeability. Storms often cause a rapid succession of cold and warm periods.
Delaware averages an annual rainfall of 44" (1117.6mm) to 47" (1193.8mm) moving from north to south. July and August are the wettest months, but the rainfall distribution is uniform over the year. The average snowfall ranges from 14" (355.6mm) in the south to 18" (457.2mm) in the north. Snowfall usually occurs between December and March with flew flurries in November and April. February often records the highest snowfall of the year. Temperature and precipitation vary depending on latitude and altitude. Delaware has 198 to 202 sunny days in the year, and the average annual humidity is between 63% and 68%.
Millsboro recorded Delaware's highest temperature of 110°F (43.3°C) on July 21, 1930, while Millsboro also recorded the lowest temperature of -17°F (-27.2°C) on January 17, 1893.
The best time to visit Delaware
The best time to visit Delaware is in the summer from June to August when the temperatures are comfortable, and the season is full of festive events. Temperatures are in the warm range of 75°F (23.9°C) to 85°F (29.4°C) with occasional hot days. Delaware coast is popular in the summer as the temperatures are cooler by 10°F (-12.2°C) to 15°F (-9.4°C) compared to the interior. Fall is another good time with lovely colors and mild to cold temperatures. Spring and fall are rainier than the summer with occasionally unexpected weather. However, accommodation rates are costlier in the peak season, and there are crowds everywhere.
The worst time to visit Delaware
The worst time to visit Delaware is from November to February during the cold season. Cold fronts from the north routinely sweep the state, and temperatures often drop below freezing. Nights are chilly at the peak of the winter even though the mountain ranges reduce the intensity of the wind and cold. Heavy snowfall occurs in February, and there is a chance of a snowstorm lurking on the horizon. The later part of the cold season needs warm clothes and patience to handle transportation delays. Winter is generally an off-season with plenty of deals for budget travelers to take advantage of the low costs of flights and hotels.
Delaware faces weather hazards in the form of thunderstorms, floods, hurricanes, and snowstorms. Thirty thunderstorms on an average occur in the year with the interior accounting more storms than the Atlantic coast. July has the highest frequency, while May to August accounts for the maximum storms in the year. Cyclones with origin in the Gulf of Mexico bring heavy and widespread rain in Delaware. Flooding occurs from tidal waves as well as tropical cyclones, usually in August and September. Snowfall is heaviest in February and March, but snowstorms occur infrequently. There are records of blizzards that brought 30" (762mm) to 36" (914.4mm) of snow in a single day.
Weather in January
January is the coldest month of the year in Delaware with frigid nights statewide. The skies are gray, and the sunshine limits to an average of 4 hours a day. The coastal regions are warmer than the interior, but temperatures may drop below 25°F (-3.9°C) in the night. Temperatures are usually in the cold zone of 25°F (-3.9°C) to 44°F (6.7°C) zone, and the precipitation is occasionally icy. The short days see a drastic reduction in sunlight as sweaters and jackets rule the roost. Wilmington in the north receives up to 6" (152.4mm) of snow during a typical year. New Year sees 3" (76.2mm) to 5" (127mm) of snow on the ground in many places. Indoor activities are in vogue, but outdoor lovers enjoy the beautiful landscape under a blanket of snow. Ice skating rinks are popular in the cold season. Heavy coats provide much-needed warmth at the peak of the cold season. The New Year week in the month of January is the coldest period in Delaware.
Weather in February
February is the snowiest month of the year in Delaware and also the period of snowstorms. Icy winds from the north blow towards the state and keep the region cold. The average temperatures are in the cold 26°F (-3.3°C) to 47°F (8.3°C) range. The skies are partly cloudy, but the rainfall rarely crosses 3" (76.2mm) in the state. Beaches have fewer crowds in the winter, and the conditions are perfect for a brisk walk in the morning. The humidity is low in the cold season, with maximum levels in the mornings. Snowfall is to the tune of 4" (101.6mm) to 8" (203.2mm), with the coastal regions receiving light amounts. Snowstorms routinely occur in February to build up large deposits of snow. Layered clothing is helpful to bear the chilly winter weather. It is a prudent idea to avoid Delaware during February when the chances of snowstorms are the highest.
Weather in March
March sees the arrival of the spring season in Delaware that steadily drives the cold away. The snowfall decreases significantly, but there is a chance of icy precipitation when a cold front invades from the north. The ground remains hard with the sun rays yet to regain full strength. Cycles of thawing and freezing alternate frequently, depending on the snow and sunlight. Day high temperatures are between 50°F (10°C) to 55°F (12.8°C), while the temperatures plummet to the 32°F (0°C) to 37°F (2.8°C) range during the night. Early spring sees an uptick in precipitation with rainfall in the 4" (101.6mm) to 5" (127mm) range statewide. Cold fronts often strike the region to bring down the temperatures briefly. The blooming of tulips adds to the beauty of the numerous gardens of Delaware. Migrating birds are a feast for the eyes on the trails and ponds. A jacket is a helpful accessory that protects from rain and cold. Expect the sunshine to increase gradually with each passing day in March in Delaware.
Weather in April
April is a warm month in the spring season of Delaware with partly cloudy skies. The last snow of the season usually disappears by the first week of April, and the landscape turns green. The average temperatures are between a warm 42°F (5.6°C) to 67°F (19.4°C) with an increase in the number of sunny days. Georgetown in the south has warm temperatures around 44°F (6.7°C) to 64°F (17.8°C), while Milford in the center is slightly cooler between 43°F (6.1°C) to 64°F (17.8°C). Thousands of horseshoe crabs fill the shorelines in spring, which is a rare sight for the eyes. Migratory birds flock the land and water, and their cries reverberate in the serene atmosphere. Dewdrops gather on the flowers in the morning, and the fresh air soothes the senses. Expect moderate rain and an occasional thunderstorm that can throw a spanner in vacation plans. The sunshine increases steadily with the daylight. The tourist footfall increases in April in Delaware with the rise in the sunshine.
Weather in May
May brings the radiance of the spring to the fore in Delaware with comfortably warm weather. The peak of the spring season coincides with a marked increase in precipitation. The average high temperatures are in the pleasant 73°F (22.8°C) to 77°F (25°C), while the nights are in the mild range of 51°F (10.6°C) to 55°F (12.8°C). Precipitation of 5" (127mm) occurs mostly in the afternoons. Tulip festivals and birding weekends prosper under the bright sunshine and beautiful conditions. The warm days have plenty of sunshine to embark upon the numerous trails in the state through modes such as hiking, walking, and cycling. The waterways offer serene views of forested landscapes, rare birds, and calm waters. The ocean waters have mild temperatures, and the soft, sandy beaches are tempting for the tourists under the moderate sun. Keep an umbrella or rain jacket at hand and an eye on the weather for thunderstorms. May offers the chance to beat the summer crowds in Delaware.
Weather in June
June is the beginning of the majestic summer season in Delaware with long and sunny days. The rainfall is noticeably lesser than the spring, as is the occurrence of storms. The average high temperatures are in the warm 82°F (27.8°C) to 85°F (29.4°C) range, while the average low temperatures are in the comfortable 60°F (15.6°C) to 63°F (17.2°C) zone. Newark in the northern interior is warmer than the coast with temperatures between 61°F (16.1°C) to 85°F (29.4°C). Precipitation and humidity increases in the summer. The sunlight lasts for a daily 9 to 10 hours, and the days are at least 15 hours long. Early risers on the beach get to watch the beautiful sunrise over the vast waters of the Atlantic Ocean. Summer is an excellent time for freshwater fishing and hunting, swimming in ponds and lakes, and other activities. Light summer clothing, along with sunscreen, is sufficient during the day. June is one of the best times to visit Delaware with pristine weather, but watch out for the summer crowds.
Weather in July
July is usually the hottest month of the year in Delaware, with peak temperatures often exceeding 100°F (37.8°C). The daylight lasts for 15 hours in the majority of the state with intense sunshine. Day high temperatures are the highest in the northern interior and remain moderate near the coast due to the influence of the Atlantic Ocean. The average temperatures are in the warm 66°F (18.9°C) to hot 88°F (31.1°C) range, with the humidity often crossing 85% in the mornings. The precipitation is mainly in the form of thunderstorms and crosses 5" (127mm) in the state. Mid-summer is the perfect time to traverse the numerous inland waterways that connect the beach towns. State parks provide abundant opportunities for kayaking and canoeing in the calm waters of the picturesque ponds. Peak summer is as good a time as any for beachwear, but do not forget the sunscreen. Delaware sees thronging summer crowds due to significant temperature differences between the coast and interior.
Weather in August
August is hot in Delaware with clear skies and sunny days amid short periods of heavy rain. An increase in humidity levels often accompanies the heat during summer. August is the wettest month with 5" (127mm) to 7" (177.8mm) of rainfall as a result of many thunderstorms that sweep the state. The wet periods are intense but brief in nature and rarely obstruct outdoor activities. The average temperatures remain in the warm 65°F (18.3°C) to 85°F (29.4°C) zone with many sunny days in the month. Dover registers between 65°F (18.3°C) to 87°F (30.6°C), while Lewes is between 69°F (20.6°C) to 85°F (29.4°C). Delaware beaches are famous due to their relative cooler temperatures than the interior. The hot and humid weather is suitable for wearing t-shirts, sweatshirts, and beachwear. The long daylight hours are fantastic for evenings on the beaches. The kite-flying season is in full swing in the clear skies and breezy evenings. Expect the humidity and temperatures to drop by the end of August in Delaware gradually.
Weather in September
September begins the lovely fall season in Delaware with mild conditions amid partly cloudy skies. The rainfall sees an increase with the departure of the hot summer temperatures. Summer thunderstorms exit the state by the early fall season, and the weather is comfortable with many sunny days in the month. The average temperatures register in the 59°F (15°C) to 79°F (26.1°C) range with a significant drop in humidity. Fall brings chilly days with crisp air and plenty of festivals. Apple orchards and pumpkin patches provide ample takings as the festival season arrives in the state. The northern part of the state sees lower temperatures compared to the south. Delightful mornings and breezy evenings are the signatures of the autumn. A light jacket keeps the rain away during the day and protects from the cold during the evening. Early fall is an excellent time to visit Delaware with the dwindling of summer crowds and drop in temperatures.
Weather in October
October is the time of colorful foliage in Delaware at the height of the fall season. The mornings and evenings are mild, while the afternoons are warm and delightful. Temperatures drop significantly to register in the 45°F (7.2°C) to 69°F (20.6°C) range across the state. The fall foliage is at its peak during the mid of October and offers unmatched views with an array of colors on display. Changing leaves display hues from red and orange to yellow and gold. Fall foliage is gorgeous in the northern part of the state with hilly regions and plenty of tree cover. Scenic byways provide opportunities to drive through the colorful landscape with the wind in the face. Waterways offer majestic views of the breathtaking scenery on the land from short as well as long distances. A light sweater or jacket is suitable for fall evenings. Expect the temperature to decrease gradually with each passing day in October in Delaware.
Weather in November
November is the last stop of the fall season in Delaware as the weather changes drastically. The temperatures subside rapidly, and cold fronts from the north become frequent. The average temperatures register between a cold 39°F (3.9°C) to a warm 59°F (15°C). The southern and eastern part of the state still has mild weather. The rainfall is in the 3" (76.2mm) to 4" (101.6mm) range, but November rarely receives measurable snow. The harvest season ends with the arrival of the cold winter, but there is plenty in store, including apple ciders, pumpkin pies, and tasty wines. Sunny days become increasingly rare, and the sunlight averages a daily 4 hours. November sees dwindling tourist numbers with the arrival of the cold weather. Expect cold fronts to hit the state and cause a dip in temperatures for short periods. Wear a jacket in the breezy but cold evening conditions. November offers budget travelers a chance to visit the pristine beaches of Delaware under moderate conditions and cheap costs.
Weather in December
December is the beginning of the cold winter in Delaware with short days amid mild sunshine. The interior and northern parts of the state receive higher snowfall than the rest. The average high temperatures are in the mild 45°F (7.2°C) to 49°F (9.4°C) range, while the average low temperatures lie in the cold 28°F (-2.2°C) to 34°F (1.1°C) zone. Dover, the capital, in the center of the state registers temperatures in the cold range of 31°F (-0.6°C) to 47°F (8.3°C). The rainfall is to the tune of 3" (76.2mm) to 4" (101.6mm) with 10 to 12 wet days in the month. Snowfall is light and rarely crosses 4" (101.6mm) at the start of the winter. Arctic chills occasionally invade the state that sees a drop in temperatures by a few degrees, especially in the north. Bring out the sweaters and jackets from the closet for the chilly nights. Christmas is a combination of rain, shine, and cold in December in Delaware, but there is no missing of the festival spirit.