Weather and climate in Delaware: Humid subtropical climate. Four distinct seasons. Mild winters. Hot, humid summers. Fall foliage in autumn. Spring thunderstorms. Occasional snowstorms. Hurricane risk in summer. Average rainfall: 45 inches annually. Coastal influences on weather.
Humid subtropical climate
Delaware is not strictly a Humid Subtropical Climate but is positioned in a transition zone between humid subtropical conditions to the south and humid continental conditions to the north. The state's climate is moderated by the Atlantic Ocean and Delaware Bay, resulting in a continental type climate with cold winters, hot summers, and ample precipitation throughout the year. For further details on how these climatic zones impact local environmental conditions, you can explore the comprehensive research conducted by the Climate Change Initiative at the University of Delaware. This project offers valuable insights into the complexities of Delaware's atmospheric dynamics.
Four distinct seasons
Delaware experiences a classic four-season continental climate, with hot and humid summers, cold but reasonably mild winters, rainy springs, and a particularly pleasant fall season characterized by mild temperatures and vibrant foliage. The coastal areas tend to be cooler in summer and warmer in winter compared to inland regions due to the moderating effects of the Atlantic Ocean.
Mild winters
Delaware's winters are considered mild, with January being the coldest month, averaging 27 degrees Fahrenheit, and the state receiving about 15 inches of snowfall annually, which is below the national average. The Atlantic Ocean's moderating influence helps to lessen temperature extremes, making the winters relatively comfortable compared to other parts of the United States.
Hot, humid summers
Delaware's summers are hot and humid, particularly inland, with temperatures often reaching around 90°F from June through August. The coast enjoys slightly cooler conditions, about 10°F lower, thanks to Atlantic breezes. During these summer months, the region also experiences the wettest weather, with a strong chance of afternoon thunderstorms and pervasive humidity. For more detailed information on Delaware's climate, you can explore this weather guide on the Iexplore website.
Fall foliage in autumn
In Delaware, fall foliage typically peaks in early October, offering breathtaking views at top locations like Bellevue State Park, Killens Pond State Park, and Trap Pond State Park. The season generally begins around September 25 and extends through November 26, showcasing vibrant autumn colors. With cooler-than-average temperatures and near-average precipitation expected, visiting these parks during this period provides a perfect opportunity to witness nature's splendor. Discover more about the best spots to experience this stunning display by visiting the article on Delaware Online.
Spring thunderstorms
In Delaware, spring thunderstorms are most common in the Spring and Summer, but can occur at any time of the year. These storms can be severe, characterized by hail of 1 inch in diameter or larger, winds of 58 mph or more, or the presence of a tornado, and are taken as seriously as tornado warnings. For more information on severe weather awareness, visit the Delaware Severe Weather Awareness Week website.
Occasional snowstorms
Delaware experiences occasional snowstorms, with the average first snowfall in Wilmington occurring around December 17. Last year, the state broke a nearly two-year snow drought with measurable snow on January 15, 2024, and weak La Nina conditions this winter are predicted to result in below-average snowfall from January to March. For more information on the state's winter weather forecast, visit the Delaware Online Weather Report.
Hurricane risk in summer
Delaware's hurricane risk, although lower than in many other U.S. states, is still significant, particularly in coastal areas like Sussex County, where hurricane-force winds and storm surges can cause extensive damage. The state's hurricane season runs from June 1 to November 30, with the highest risk typically occurring from August to late September due to warmer ocean temperatures. For more detailed information regarding hurricane preparedness, please visit the official Delaware Emergency Response Guide.
Average rainfall: 45 inches annually
Delaware receives an average annual rainfall of 45 inches, making it wetter than most states in the United States. This substantial amount of precipitation occurs on average 116 days per year. For more detailed information about the climate in Delaware, you can visit the Best Places website. Delaware's consistent rainfall contributes to its lush landscapes and diverse ecosystems.
Coastal influences on weather
Delaware's climate is significantly influenced by its coastal location, with the Atlantic Ocean moderating temperatures, especially in winter, and the Gulf Stream contributing to warm, humid summers. The Sea Breeze Effect causes notable temperature contrasts between coastal and inland areas, particularly in late spring and late fall.