By Joseph Sapia Summer season crowds leave. Oppressive heat disappears, but it is still warm. The sun projects a softer light. Wildlife migrates. The foliage is changing colors.The magic of September at the Jersey Shore.“Don’t tell anybody,” laughed Cindy Zipf, executive director of the Clean Ocean Action.But, then, she added, “The secret’s out.”Secretly or not secretly, Shore people speak in wonder of September along the coast.“It is kind of magical,” said Margaret Mass, executive direc- tor of the Red Bank Visitors Center. “It’s a way to still enjoy the waterfront experience.“It’s kind of nice people can get into their favorite restaurants without a line,” Mass said. “It’s not too cold, not too hot.”Caitlin Over, 31, of Atlantic Highlands and Alissa Snell, 36, of Red Bank were leaving the Sea Bright beach, where both have season badges, on a recent day. While both are educators – Over, a guidance counselor at Howell High School and Snell, a school psychologist at Neptune High School – their summer is not over.September, Over said, “it’s my favorite local summer.”“The water’s warm, the beach is quiet, it’s just easy,” Snell said. “Everybody on the beach we know is a local.“It’s just more relaxed,” she added. “More people know their beach etiquette – don’t sit close to someone else, don’t blare music, throw garbage away, watch your kids.”Some wrongly think September is the end of beach season, said Olivia Rauso, 19, of Red Bank.“I think it’s really great, if you take adavantage of it,” said Rauso. “On Sandy Hook, it’s migrating season,” Dillingham said.Monarch butterflies and fall warblers are heading south, for example. “You start to notice that change,” Dillingham said.Zipf, whose Clean Ocean Action environmental group also is based at Sandy Hook, noted the changing of colors – the “bright yellow” of goldenrod and the ocean’s water, for example.“The water gets a reflection from the sun that’s deeper, crisper,” said Zipf, who has spent all of her 57 years at the Shore. “Foliage starts turning red. The air is crisper. It’s a beautiful time of year.”Pat MacMillan, 66, a recently retired Perth Amboy schools administrator who lives in Fair Haven, noted how September is a great time for town and beach.“We always try to get to the beach in September,” MacMillan said. “It’s quiet. You can go to the end of September. “You can go to restaurants, walk around without the crowds,” MacMillan said. “September is the best.”This September, MacMillan will do local trips to Ocean Grove and Island Beach State Park, along with vacationing at Acadia National Park on the Maine coast.Rauso, on the other hand, is headed back to school at Montclair State University. “As soon as I’m at Montclair, I miss the beach,” Rauso said. “It’s the best-kept secret, September at the beach,” Rauso said.But the secret is out…. For locals, September is sort of a Take Back the Shore.“You can look at it as our time,” said Laurie Potter of Rumson. “It can be a time to enjoy our own backyard.”But Potter, co-owner of River Road Books in Fair Haven, noted the “juxtaposition,” when the Jersey Shore’s traditional summer season of Memorial Day to Labor Day transitions with the coming of September.“You can go out to all the places you don’t want to get near in the summer,” Potter said.However, tourism also helps businesses, Potter said. And tourism takes advantage of September. For example, in Red Bank, the Guinness Oyster Festival is Sunday, Sept. 25, at the White Street Parking Lot.“We definitely enjoy a nice shoulder season, Red Bank being the gateway to the Shore area,” Mass said. “Temperatures go down, free beaches.“Beautiful weather,” Mass said. “We, sometime, have the nicest weather, September weather.”“It can be the best weather of the year, in September,” Potter agreed.“People feel it’s a good time to get out,” Mass said.The natural world, too, changes.“The way I always know it’s September is the gulls and terns wing dance,” said Tim Dillingham, executive director of the American Littoral Society, a Sandy Hook-based coastal conservation group. “They’re flying around, grabbing these (flying) ants.