There are many Fiesta traditions, from swapping medals to staking a claim on a spot to see the Battle of Flowers Parade, but using the Rain Rock to keep a Night in Old San Antonio dry might be the most eyebrow-raising to people who don’t know the reason why.

It’s the Monday before A Night in Old San Antonio opens, and that means it’s time to raise the “Rain Rock.”

As Fiesta 2023 is off to a chilly and wet start, NIOSA is continuing its tradition of hanging the “Rain Rock” to prevent further disruptions from bad weather.