Photo by Jessica Witmer

As many as 30,000 people are expected to crowd the National Mall tomorrow, and while the forecast is for rain, don’t expect this bunch to pray for sunny skies—they’re atheists, after all.

The Reason Rally, a so-called Woodstock of secularism, is being held to celebrate what its organizers see as a surge in non-belief, agnosticism and other assorted godlessness that is often shooed away from engaging in public leadership in a country where politicians are expected to wear their faiths on their sleeves.

The Reason Rally is sponsored by a collection of secular-focused organizations that, if you’ll forgive the reference, just want to rally to restore some sanity to the public square.

But it’s not, the planners say, an “opportunity to trash religion.” On the event’s website, they write:

This will be a positive experience, focusing on all non-theists have achieved in the past several years (and beyond) and motivating those in attendance to become more active. While speakers have the right to say what they wish, the event is indeed a celebration of secular values.

One of the rally’s organizers, David Silverman, said on Morning Edition today he feels atheism is at a fulcrum similar to where gay Americans were on the eve of the Stonewall riots in New York in 1969.

“We’ll look back at the Reason Rally as one of the game-changing events when people started to look at atheism and look at atheists in a different light,” he told NPR’s Barbara Bradley Hagerty. He said that the U.S. is starting to catch up with Canada and Western Europe, places where, Silverman said, religion is going “extinct.”

To that end, tomorrow’s rally, running from 10 a.m. to sunset on the east face of the Washington Monument, features a slate of well-known nonbelievers, including the evolutionary biologist Richard Dawkins, the comedians Eddie Izzard and Paul Provenza, Mythbusters host Adam Savage, former NPR reporter Jamila Bey and Rep. Pete Stark (D-Calif.), the only openly atheistic member of Congress. Bill Maher will appear in a video message.

And it closes with a performance by who else? Bad Religion.