The Atlantic Ocean greatly affects New Jersey’s climate. (Photo: Thomas Northcut/Photodisc/Getty Images )
New Jersey possesses a moderate climate with warm, humid summers and relatively cold winters. The fourth-smallest state in the country, New Jersey’s total land area covers 7,419 square miles; at its maximum, the state measures 170 miles from north to south, and 70 miles from east to west. Despite its modest size, climactic variations exist in different geographic regions of New Jersey, and various atmospheric and oceanic elements impact the state’s climate.
The climate of New Jersey, like that of much of the United States, is dominated by the prevailing westerlies, an atmospheric conveyor belt on which weather systems travel from the western edge of the continent to the eastern edge of the continent. However, New Jersey’s proximity to the Atlantic Ocean also affects the state’s climate by moderating temperatures and providing abundant moisture for gathering storm systems.
The Appalachian Mountains rise to over 1,500 feet in the northwestern part of New Jersey. Hence, overall temperatures in this region are slightly colder than in the rest of the state, particularly during the winter — for instance, freeze-free days in the highlands average only about 163 per year, whereas the central part of the state sees 179 days above freezing, and the coastline averages 217. These hills and mountains also receive more annual precipitation than the rest of the state, especially in the form of snow, which averages 40 to 50 inches per year. In contrast, only 10 to 15 inches of snow fall each year in New Jersey’s extreme south. Along the state’s long border with the Atlantic Ocean, onshore spring and summer breezes cool coastal communities, and can occasionally penetrate up to 40 miles inland. In autumn, the same areas remain warmer than the rest of the state, due to the nearby presence of the relatively warmer sea.
In January, the coldest month, overall statewide highs average in the upper 30s and low 40s, with overnight lows bottoming out in the mid 20s. In July, the warmest month, statewide highs average in the mid 80s, with lows in the mid 60s. Spring and fall temperatures lie in between these two extremes, and are often mild and comfortable. For instance, October can still be quite pleasant, with an average high of 66 and an average low of 44. The warmest spot in New Jersey is Cape May, while the coolest is Sussex in the northern part of the state.
Precipitation in New Jersey averages 45 inches per year. The southeast coast receives the least amount of precipitation, around 40 inches, while the north-central region receives the most precipitation, nearly 51 inches. Measurable precipitation falls about 120 days each year, with autumn being the driest season. The driest location in New Jersey is Atlantic City, while the wettest is Morris Plains in the central part of the state. Thunderstorms occur in most locales approximately 25 to 30 times per year, with more storms near the coast than farther inland.
Based in western New York, Amy Harris began writing for Demand Media and Great Lakes Brewing News in 2010. Harris holds a Bachelor of Science in Mathematics from Penn State University; she taught high school math for several years and has also worked in the field of instructional design.