DALLAS (CBSDFW.COM/AP) — Several thousand people braved rain and near-freezing temperatures in Dallas to mark the 50th anniversary of the assassination of President John F. Kennedy.

Blustery conditions during the outdoor commemoration Friday at Dealey Plaza forced cancellation of a performance by the Dallas Symphony Orchestra. Organizers also announced a flyover salute was canceled due to weather.

Umbrellas were not allowed for security reasons so people who attended the midday event bundled up in plastic ponchos, plus heavy coats and hats, as light rain fell.

Images of JFK and his family were shown on screens in front of the crowd, including scenes from a Kennedy family Christmas.

Dallas Mayor Mike Rawlings and author and historian David McCullough spoke during the ceremony, which lasted less than an hour.

Rawlings says the nation grew up on the day Kennedy died and had to live up to the challenges of the words and vision of a beloved president. Rawlings says Dallas has turned “civic heartbreak” into hard work and it is a much different place today.

He called Kennedy an “idealist without illusions who helped build a more just and equal world.”  Rawlings’ remarks were followed by a moment of silence and a tolling of bells.

McCullough spoke next saying John F. Kennedy’s words changed lives and history. And he said much of what Kennedy said still applies today.

McCullough read excerpts of some of Kennedy’s most well-known speeches during the ceremony. He says Kennedy spoke of things that mattered, including education, service to one’s country and the cause of peace on Earth. And he says Kennedy spoke to the point, with confidence and without “stale platitudes.”

The ceremony ended ended with the Navy choir singing “The Navy Hymn.” Kennedy served in the Navy during World War II.