Philadelphia Climate & Monthly Temperature Overview – United States

Summer in Philadelphia

During the summer months in Philadelphia, the weather is generally hot and humid, with temperatures reaching an average high of 86°F (30°C) in July. Precipitation is frequent, with an average of 4 inches (100 mm) of rain per month. However, despite the heat and humidity, Philadelphia offers a variety of outdoor activities to enjoy during the summer, such as visiting the city’s many parks, taking a boat ride on the Delaware River, or attending a concert at the Mann Center for the Performing Arts.

Fall in Philadelphia

The fall season in Philadelphia brings cooler temperatures and lower humidity, making it an ideal time to explore the city’s many historical and cultural attractions. The average high temperature in October is 65°F (18°C), and the leaves of the trees begin to turn vibrant shades of red, orange, and yellow. Fall is also a great time to enjoy outdoor activities such as hiking, biking, and kayaking.

Seasonal Variations

Philadelphia experiences a humid subtropical climate with distinct seasonal variations. Winters are generally cold, with average temperatures hovering around 35 degrees Fahrenheit in January. Snowfall is relatively common, particularly during the months of January and February. Summers, on the other hand, can be hot and humid, with average high temperatures exceeding 85 degrees Fahrenheit in July and August. Spring and fall seasons provide milder weather, offering pleasant days and cool nights.

Interannual Variations

Year-to-year variations in temperature are also observed in Philadelphia. While the average annual temperature is around 55 degrees Fahrenheit, significant fluctuations can occur depending on the prevailing weather patterns. For instance, during El Niño years, which are characterized by warmer ocean temperatures in the Pacific Ocean, Philadelphia tends to experience milder winters and hotter summers. Conversely, during La Niña years, winters are typically colder, while summers are relatively cooler.

Climate Overview

Philadelphia, located on the Atlantic coast of the United States, experiences a humid subtropical climate. The city has four distinct seasons, with warm, humid summers and cool, often chilly winters. Philadelphia’s climate is influenced by its proximity to the Atlantic Ocean, which brings a constant supply of warm and humid air. The city is also subject to frequent storms, including thunderstorms during the summer and snowstorms in the winter.

Cloud Cover

Philadelphia receives an average of 43.5 inches of precipitation annually, much of which falls during the summer months. The city’s cloud cover is generally moderate, with an average of 50% cloudiness throughout the year. However, the amount of cloud cover can vary significantly by month, with the cloudiest months being January, February, and December. These months see an average cloud cover of 65% or more. The least cloudy months are September and October, when cloud cover averages 35% or less.

Normal Precipitation

Philadelphia experiences an average of 44 inches of precipitation annually, distributed fairly evenly throughout the year. The wettest months are May, June, and September, while the driest are January and February. Precipitation can occur in various forms, including rain, snow, sleet, and hail.

Variation in Precipitation

Precipitation in Philadelphia is subject to considerable variation from year to year. In recent years, the city has witnessed both exceptionally wet and dry periods. For example, in 2018, Philadelphia received over 60 inches of rain, while in 2016, it received less than 30 inches. Long-term records indicate that these variations are part of natural climate patterns, influenced by factors such as El Niño and La Niña.

Average Rainfall and Seasonal Distribution

Philadelphia experiences a moderate amount of rainfall throughout the year, with an average annual precipitation of around 40 inches. The rainfall is fairly evenly distributed across the seasons, with slightly higher amounts during the warmer months from May to September. The wettest month is typically July, with an average of over 4 inches of rain, while the driest month is January, with an average of around 2.5 inches.

Variability and Extreme Events

The amount of rainfall in Philadelphia can vary significantly from year to year. Droughts can occur occasionally, particularly during the summer months, while heavy rainfall events can also lead to flooding. For example, in 2018, Philadelphia experienced a devastating flash flood that caused widespread damage. Climate change is likely to intensify the frequency and severity of extreme rainfall events in the future, posing challenges for urban infrastructure and water management systems.

Historical Snowfall in Philadelphia

Philadelphia, known for its humid, subtropical climate, experiences occasional snowfall during the winter months. The city’s snowfall is generally moderate compared to regions further north or at higher elevations. Historical records indicate that the average annual snowfall in Philadelphia is approximately 20-25 inches. However, significant variations and extreme snowfall events occur from year to year.

In recent years, Philadelphia has witnessed several notable snowfall events. The winter of 2015-2016 was particularly snowy, with the city receiving over 50 inches of snowfall. This snowfall broke the previous record set in 1996, when Philadelphia received 33.7 inches of snow. The heavy snowfall caused widespread disruptions, power outages, and transportation delays. However, it also brought a sense of wintery joy to many residents.

Overview

Philadelphia, located in the northeastern United States, experiences a temperate climate, with distinct seasons. The city’s latitude and proximity to the Atlantic Ocean influence its weather patterns. Summers in Philadelphia are typically warm and humid, with average temperatures ranging from the mid-70s to mid-80s Fahrenheit (mid-20s to low-30s Celsius). The city receives an average of 43 inches (109 centimeters) of rainfall annually, with most occurring during the summer months.

Sunshine Duration and Intensity

Philadelphia enjoys an average of 2,500 hours of sunshine per year, equivalent to about 6 hours per day. The city experiences the most sunshine during the summer months, with an average of 7-8 hours per day. However, even during the winter months, Philadelphia receives a significant amount of sunlight, with an average of 4-5 hours per day. The intensity of sunlight in Philadelphia varies throughout the year, with the strongest UV radiation occurring during the summer months. It is important to use proper sun protection, such as sunscreen and sunglasses, when spending extended periods outdoors, especially during peak hours.

Moonrise and Moonset

In Philadelphia, the moon can be observed throughout the month, rising and setting at different times. The exact times of moonrise and moonset vary depending on the day and the season. For instance, during the summer months, the moon typically rises later in the evening around 9 pm. In contrast, during the winter months, the moon rises earlier in the afternoon around 5 pm. Similarly, the moonset time also varies throughout the year. Typically, the moon sets later in the evening during the summer months and earlier in the evening during the winter months.

Moon Phases

As the moon orbits around the Earth, its position relative to the Earth and the Sun changes, resulting in different phases of the moon. In Philadelphia, the various phases of the moon can be observed throughout the month, including the new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and waning crescent phases. During the new moon phase, the moon is positioned between the Earth and the Sun, making it impossible to see from Earth. As the moon progresses through its orbit, it gradually becomes visible, moving from the crescent phase to the full moon phase. During the full moon phase, the entire illuminated side of the moon is facing the Earth, making it appear as a bright, circular disk. After the full moon, the moon continues its orbit, transitioning through the waning phases before returning to the new moon phase.

Humidity Patterns

Philadelphia experiences humid subtropical climate, characterized by high humidity levels throughout the year. The average relative humidity hovers around 70%, peaking in the summer months when it can reach 80%. The high humidity is a result of the city’s location near the Atlantic Ocean, which provides ample moisture for evaporation and condensation. Additionally, the city’s dense urban environment creates a heat island effect, trapping warm and humid air within the city limits. The combination of these factors leads to frequent periods of oppressive humidity, particularly during summer heat waves.

Impact on Health and Comfort

Prolonged exposure to high humidity can have adverse effects on human health and comfort. Excessive humidity makes it difficult for the body to cool down through perspiration, leading to heat cramps, heat exhaustion, and heat stroke in extreme cases. Additionally, the moist air promotes the growth of mold and mildew, which can aggravate respiratory issues and allergies. The combination of high temperature and humidity can make outdoor activities uncomfortable and even dangerous, especially for those with pre-existing respiratory conditions. Residents and visitors alike are advised to take precautions during periods of high humidity, such as staying hydrated, wearing loose and light-colored clothing, and seeking shade or air-conditioning when possible.

Wind Patterns

Philadelphia’s wind patterns are primarily influenced by its location on the mid-Atlantic coast and the prevailing westerly winds. During the spring and summer, prevailing winds from the southwest bring warm and humid air from the Gulf of Mexico, resulting in frequent thunderstorms and occasional coastal flooding. In the fall and winter, winds shift more to the northwest, bringing colder and drier air from Canada. These winds can cause strong gusts and occasionally produce snow squalls. Philadelphia’s proximity to the Atlantic Ocean also influences its wind patterns, with sea breezes prevalent during the day and land breezes at night.

Wind Speed and Direction

Wind speeds in Philadelphia vary throughout the year, with the strongest winds occurring during the winter months. Average wind speeds range from 9 to 12 mph, with frequent gusts exceeding 20 mph. The dominant wind direction is from the west-northwest, although southwesterly winds are also common during the summer months. Strong winds can impact outdoor activities, particularly during the winter when they can cause wind chill and increase the risk of hypothermia. However, these winds also play a role in clearing out air pollution and providing ventilation for the city.

Best time to visit

The best time to visit Philadelphia is during the shoulder seasons, spring (April-May) and fall (September-October), when the weather is mild and pleasant. During these months, you’ll enjoy comfortable temperatures, fewer crowds, and lower hotel rates.

Spring (April-May)
Spring is a beautiful time to visit Philadelphia. The city comes alive with blooming flowers, and the weather is perfect for exploring the city’s many outdoor attractions, such as the Philadelphia Zoo, the Morris Arboretum, and the Independence National Historical Park. The average temperature in April is 55 degrees Fahrenheit (13 degrees Celsius), and in May it is 65 degrees Fahrenheit (18 degrees Celsius).

Fall (September-October)
Fall is another great time to visit Philadelphia. The leaves on the trees are turning vibrant shades of gold and red, and the weather is still mild enough to enjoy outdoor activities. The average temperature in September is 75 degrees Fahrenheit (24 degrees Celsius), and in October it is 65 degrees Fahrenheit (18 degrees Celsius).

Current State and Potential

Philadelphia has been actively promoting solar energy as part of its sustainability goals. In recent years, there has been a significant increase in solar installations on rooftops and other urban surfaces. In 2021, the city had over 4,000 solar systems with a combined capacity of around 35 megawatts (MW). This has contributed to Philadelphia ranking among the top 10 cities in the United States for solar installations. However, the city still has significant potential for further solar development, particularly on commercial and institutional buildings, and through community solar gardens.

Challenges and Opportunities

Despite its progress, Philadelphia faces several challenges in expanding solar energy. One major obstacle is the limited availability of suitable rooftops, especially in dense urban areas. Additionally, the city has a complex regulatory environment that can make solar installations complex and costly. However, there are also opportunities for Philadelphia to overcome these barriers. The city has established several programs and incentives to encourage solar development, including financial assistance, streamlined permitting processes, and community outreach initiatives. By addressing these challenges and leveraging the available opportunities, Philadelphia can continue to increase its reliance on solar energy and reduce its carbon footprint.

Topography of Philadelphia

Philadelphia is located on the Atlantic Coastal Plain of North America, a broad, gently sloping region that extends from New Jersey to Georgia. The city lies within the Delaware River Valley, a narrow corridor of land that stretches along the Delaware River from Trenton, New Jersey, to Wilmington, Delaware. The topography of Philadelphia is characterized by a series of rolling hills and valleys, with the highest point being Belmont Plateau at 409 feet (125 meters) above sea level. The Schuylkill River, which flows through the western part of the city, has created a deep valley that separates the city from the Wissahickon Creek Valley to the west. The Delaware River forms the eastern boundary of the city and creates a broad, flat plain that extends to the Atlantic Ocean.

Geological History

The topography of Philadelphia is the result of a long and complex geological history. The area was once covered by a vast ice sheet that covered most of North America during the last ice age. As the ice sheet retreated, it left behind a layer of glacial till, a mixture of sand, gravel, and clay. This till formed the basis of the rolling hills and valleys that characterize the area. The Delaware River and its tributaries have also played a role in shaping the topography of Philadelphia. The river has eroded the soft sedimentary rocks that underlie the area, creating the deep valleys and gorges that are found along its course.

Philadelphia International Airport (PHL)

Nestled just seven miles southwest of downtown Philadelphia, Philadelphia International Airport (PHL) is the primary aviation hub serving the “City of Brotherly Love” and its surrounding areas. PHL boasts a robust network of domestic and international flights, making it a convenient gateway for both business and leisure travelers. With five terminals and 125 gates, PHL handles over 33 million passengers annually. The airport offers an array of amenities, including duty-free shops, restaurants, lounges, and ground transportation options.

Getting to and from PHL

Reaching Philadelphia International Airport is a breeze, with various transportation options available. The SEPTA Airport Regional Rail Line provides a convenient link between the airport and Center City Philadelphia, taking approximately 25 minutes. Alternatively, taxis, ride-sharing services, and shuttle buses are readily accessible. The airport also features a parking garage with both short-term and long-term options. For those seeking a luxurious experience, PHL offers limousine and helicopter services.

History and Culture

Philadelphia, fondly known as the “City of Brotherly Love,” is steeped in American history and brimming with cultural attractions. Founded in 1682 by William Penn, Philadelphia played a pivotal role in the American Revolution. Independence Hall, where the Declaration of Independence and the Constitution were drafted, stands as a testament to the city’s rich heritage. The vibrant museum district boasts renowned institutions such as the Philadelphia Museum of Art, the Mutter Museum, and the National Liberty Museum, offering an eclectic array of exhibits covering art, history, and medical curiosities.

Architecture and Landmarks

Philadelphia’s architectural landscape is a captivating blend of historic and modern structures. The iconic Liberty Bell and Independence Hall are must-see landmarks, evoking the city’s revolutionary past. The imposing City Hall, one of the largest municipal buildings in the world, towers over the skyline. The picturesque Elfreth’s Alley, the nation’s oldest continuously inhabited residential street, offers a glimpse into colonial life. Contemporary skyscrapers, such as the Comcast Technology Center and the Cira Centre, rise alongside historic buildings, creating a dynamic urban environment. Philadelphia’s green spaces, including Rittenhouse Square and Fairmount Park, provide respite from the bustling city streets and offer ample opportunities for recreation and relaxation.