The Mets are in first place, and their loyal fans — invigorated by a scintillating summer pennant race — are all over the place.

Waking up after a long slumber through below-.500 August dog days (or coming out of the woodwork to hitch a ride on the bandwagon), Mets fans have made their boisterous presence felt and heard over the past two weeks with stops in Baltimore, Philadelphia — and even Denver. Herded by the fan group known as “The 7 Line Army,” even the manager is noticing the difference.

“Our fans are incredible,” Terry Collins said Aug. 18 in Baltimore. “The 7 Line was here tonight, they’re unbelievable when they show. You’ve got to like it. If you’re a player, gosh almighty, how can you feel tired or fatigued when you have that atmosphere going? So it’s really cool.”

Wednesday night’s game in Philadelphia will be the third of a four-game set against the rival Phillies, who are in last place in the NL East and are 25th in average attendance with 25,010. That left plenty of room in the stands for an Amtrak-carried influx of blue-and-orange, and they were given something to cheer about as their Mets won 16-7 and 6-5.

After a home run from David Wright and a double by Michael Cuddyer in the second inning on Monday, Phillies radio announcer Larry Andersen said, “I’ll take the Nationals fans over the Mets fans.” When asked why, Andersen answered: “They’re just obnoxious.”

It was also noticed the previous weekend in Denver, where the 7 Line helped to buy up two sections of the outfield at Coors Field and make a ruckus, chanting “Let’s Go Mets!” even before the first pitch was thrown.

“Well, New Yorkers are louder than everybody else,” said Rockies manager Walt Weiss, who is from Tuxedo, NY. “So 100 New Yorkers are the equivalent to about 10,000 Mets fans. And that’s coming from a New Yorker.”

The Mets return home Friday to open a six-game homestand against the Red Sox and Phillies, before embarking on a 10-game road trip through Miami (hello, South Florida transplants!), Washington and Atlanta.

The big test of the Mets’ traveling fan contingent will come during that Sept. 7-9 series in a playoff-like atmosphere against the Nationals in the capital.