WASHINGTON — Saturday’s forecast calls for a partly sunny high of around 60.

Unseasonably warm? Yep. But it still might be too chilly to run around without much of your clothing.

Nevertheless, several brave, confident souls are gathered on 14th Street in D.C. Saturday afternoon as part of the eighth-annual “Cupid’s Undie Run.”

It’s more or less what you think it is: people running in their underwear. Undies are not mandatory, however. (Some runners opt for costumes.)

The “brief” mile-ish run/party benefits the Children’s Tumor Foundation, which aims to raise awareness of neurofibromatosis. NF is a rare genetic disorder that causes tumors to grow on nerves and can result in blindness, deafness, chronic pain and learning disabilities.

Similar events are being held this month in 38 other cities worldwide.

Last year, an estimated 1,600 took part in D.C., and $3.5 million was raised for the foundation. Organizers hope to top $4 million this year.

(See road closing information on the District’s website)