The beats from D.J.s thrummed. Brass bands boomed. Bars and restaurants bustled. Sequins, feathers and fans that opened with a thwack were everywhere.

And to organizers’ relief, a cold morning rain ceased just in time for Saturday’s WorldPride parade in Washington, D.C., making way for a sticky heat that seemed to rise off every surface. Soon, the air smelled like sunscreen.

Revelers and those trying to sell them things agreed the celebratory atmosphere was vital for the L.G.B.T.Q. community and the nation’s capital itself.

“This Pride is very much needed,” said Fred Rogers, 31, who lives in Fredericksburg, Va. “We all need a chance to show the world that we are still here, and we’re not going anywhere.”

Amid the joy and celebration, there was still an undercurrent of anger and worry. The parade route wound its way to less than a third of a mile from the White House, and President Trump’s moves to curb the rights of the L.G.B.T.Q. community weighed heavily on some of the paradegoers and prompted other people not to attend at all.

Ryan Bos, executive director of the nonprofit Capitol Pride Alliance, which organizes the city’s annual Pride events, including this year’s global one, said in an interview Saturday that planners had originally expected three million attendees over the three-week WorldPride festival, but the actual turnout fell short of that. Many business owners said that while the crowds were roughly normal for the city’s annual Pride Parade, and the parade route itself was packed, attendance did not remotely live up to expectations for a festival that typically draws people from around the world.