Earth Day is in full middle age and many fear it might start to sag, but it still has plenty of life if the number of events this year is an indication.

This year, the annual April 22 event falls on Monday.

Earth Day began in 1970 as a reaction to an oil spill, but it has morphed into Earth Week with events scheduled starting this Saturday through next weekend in Philadelphia, its Pennsylvania suburbs, South Jersey, and the Shore. Even though it’s both Passover and Easter weekend, there are still plenty of opportunities to take part.

Most exciting, is the City Nature Challenge. For the first time, Philadelphia will compete against more than 150 cities across six continents in a contest started in 2016 by the California Academy of Sciences and Natural History Museum of Los Angeles County. To take part, participants need to download the free iNaturalist mobile app and upload pictures of nature. The data are geocoded and searchable, essentially creating a log of wildlife and flora from around the globe.

The contest takes place Friday, April 26, through Monday, April 29. Photographs of all species are cataloged and results of the contests will be announced May 6.

Julie Slavet, executive director of the nonprofit Tookany/Tacony-Frankford Watershed Partnership, pushed for Philly to take part. Montgomery, Bucks, Delaware, Camden, Gloucester, and Burlington Counties are also competing for the first time. The public is invited to participate.

“The goal is to get people engaged with nature,” Slavet said. “It’s an incredible app that anybody can use. It let’s people look in their own backyard, sidewalk, or park to connect with nature.”

She said the data are invaluable in creating a worldwide catalog of wildlife, plants, fungi, insects, slime mold, carcasses, shells, tracks, and fur.

“It’s something a grandparent can do while walking with a grandchild," Slavet said. "It’s something teachers can do with a class.”

City Nature Challenge organizers expect 25,000 people will participate and log 750,000 observations. Go to cncphilly.org to learn how to take part.

Below are a list of other Earth Day events happening in the area:

Saturday, April 20

Head over to the John Heinz National Wildlife Refuge at Tinicum for the Darby Creek Clean-up & Rails to Trails Day. Meet under the Pavilion near the Visitor Center or at the parking lot on the east side of Route 420 to sign in and receive gloves and trash bags.

The annual Run for Clean Air in Philadelphia hosted by Clean Air Council and sponsored by Toyota Hybrids started in 1981 and bills itself as the city’s largest Earth Day event. More than 1,500 runners are expected for four events at MLK Drive, next to the Art Museum: 10K run, 5K run, 3K walk, and Kids’ Fun Run. Runners who can’t make it in-person will still have a chance to participate in a Virtual 5K race in the week before and after Earth Day. All of Toyota’s hybrid vehicles will be on display, with the Hybrid Rav-4 serving as pace car for the 10K Run.

An Earth Day celebration at Batsto Historic Village near Wharton State Forest at 31 Batsto Road in Hammonton, Atlantic County, runs 12:30-4 p.m. Admission is free and includes nature talks, walks, and other family events.

Join Lululemon Cherry Hill, SHINE Power Yoga, and OHMGrown Yoga for a second annual Earth Day Celebration with yoga and a cleanup at Palmyra Nature Cove. Meet at the education center at noon for a walking meditation along the perimeter trail, followed by a yoga class. Bring a water bottle and mat. Cleanup is 2-3 p.m. along the Delaware River.

The Cape May County Park and Zoo is holding a 5K Earth Day Race and 1 Mile Fun Run. Preregistration donation is $20 in advance or $25 the day of the race and goes to benefit the Cape May County Park and Zoo Trust Fund. Events include music, story time, inflatable obstacle course and slide, drum circle, hands-on educational exhibits, free entertainment, naturalist hike, food, and crafts.

Also in Cape May County, the Cape May Brewing Co. is joining forces with Iron Hill Brewery in Voorhees and Surfrider Foundation South Jersey with a cleanup of Higbee Beach, a haven for bird-watching. Cleanup equipment will be provided. After the cleanup, crews will head back to Cape May Brewing Co. Tasting Room & Brewtique for a sneak peek at the new Twin Finn beer.

Monday, April 22 (Earth Day)

The Phillie Phanatic makes an appearance at the Schuylkill Center for Environmental Education in Fairmount Park. The 1 p.m. event is free and begins in the amphitheater, an outdoor seating area with a series of rock steps. The Phanatic will lead the audience in dancing the air cycle, creating a magical rainstorm, and telling a food-chain story with lots of sound effects.

Glassboro in Gloucester County is hosting a free Earth Day Electric Vehicle Ride from noon to 3 p.m. at 1 High Street West. The borough’s mayor and council will be on hand at the event designed to let people see and drive electric vehicles including a Tesla, Nissan Leaf, BMW i3, Chevy Bolt, and others. There will also be electric bikes to view and test out.

FILE - 2019 S75D Tesla. (AP)
David Zalubowski / AP
FILE - 2019 S75D Tesla. (AP)

Also in Glassboro, the William G. Rohrer College of Business at Rowan University will host an Earth Day PRME one-day conference featuring keynote speaker Joseph Fiordaliso, president of the New Jersey Board of Public Utilities. He will speak on a green economy and sustainable society. The conference costs $40 and will explore renewable energy, policy, and the state Energy Master Plan and include a panel discussion on the economy.

Tuesday, April 23

MISSION Story Slam 3: Saving Us From Ourselves, a storytelling competition, is scheduled at Yards Brewing Co. in Philadelphia. The competition is open to people who work in Philly’s nonprofit and green community. Ten storytellers drawn at random will compete for $350 in donations to the nonprofit of their choice. Cost is $15 in advance and $20 day of. A free tour of the brewery starts at 6 p.m.

Wednesday, April 24

The Philadelphia Water Department opens its water bar in the City Hall courtyard. The PWD found in surveys that nearly 40 percent of city residents drink bottled water at home, despite the fact that city tap water, which meets EPA safety standards, costs about a half a penny per gallon. The water bar will serve tap water to residents in an effort to demonstrate the water is safe and high quality. City officials will be on hand. The water bar will remain through spring and summer on Thursdays.

Thursday, April 25

Gov. Tom Wolf, Mayor Jim Kenney, Councilman Derek Green, and other officials and dignitaries will be on hand for the ribbon-cutting of the HVAC Pathways Vocational Lab in Kensington. The lab will train 27 people from the Philadelphia School District or ASPIRA School with the goal of providing city youth and unemployed residents hoping to work in clean energy. The job-training program is sponsored by Johnson Controls and the nonprofit Energy Coordinating Agency.

Friday, April 26

City Nature Challenge kicks off. The Sierra Club’s Southeastern Pennsylvania group has listed some specific locations within the city to participate in the challenge including Rittenhouse, Wissahickon Creek, Fairmount Horticultural Center, and FDR Park. The New Jersey Conservation Foundation has a list of organized City Nature Challenge walks in South Jersey.

The Wissahickon Environmental Center in Philadelphia is hosting a Sunset Toad Walk from 7 to 9 p.m.

Saturday, April 27

The Schuylkill Center for Environmental Education hosts Naturepalooza, its signature event of the year. Running from 10 a.m. to 1:45 p.m. the event features nature walks, pond explorations, arts-and-craft activities, fort-building adventures, science challenges, activity tables from dozens of environmental groups, and more. It is held in partnership with the Philadelphia Science Festival.

Burlington County is looking for volunteers to participate in the Clean Communities Spring cleanup from 9 a.m. to noon at Willingboro Lakes Park. Bags, gloves, and grabbers will be provided, along with light refreshments and water for refillable water bottles. To register, email cleancomm@co.burlington.nj.us or call 609-499-1001 x 266.

The Gloucester City Library will host a program devoted to ways to live earth-friendly. Participants will create their own pots with recyclable materials to take home and grow.