But in true San Francisco fashion, the fog was so thick that fireworks fired from the top of the tower in celebration were completely obscured with only the glow of the new lights peeking through the clouds.
A symbolic switch for the Salesforce Tower, which for better or worse, has become a symbol of a changing San Francisco.
Salesforce employees were celebrating all night, as 11,000 LED lights were turned on, atop the city's skyline. San Francisco artist Jim Campbell created the light display, which features moving images from photos taken around the city.
VIDEO: Salesforce Tower light installation brightens up San Francisco skyline
"The Bay Bridge's lights are on every night, so it's just adding to the architecture and the landscape of the city. I think the skyline is going to be pretty cool," said San Francisco resident Natasha Keswani.
"The lights could add a little something special to it, change colors when the Giants win, when the Warriors win," says Annette Neely, a longtime San Francisco resident who works near the tower and is not a fan, "you can see it from everywhere and it's not pretty."
Even though the permanent light installation will make the tower even more noticeable, with visibility at night from 20 miles away, Neely is hopeful the lights will add a little character to the building. "I think they're going to make it better, just from a night time, lights on the bridge, lights on Coit Tower, city hall...."
RELATED: San Francisco's Salesforce Tower becomes tallest building on West Coast
The lighting of the tower top, is the finale of the grand opening celebration. Salesforce CEO Marc Benioff leased 60 percent of the 61-story building from Boston Properties. His symbol of progress in the sky is also one of responsibility.
Benioff is pledging millions to end homelessness.
He spoke Tuesday after a ribbon-cutting ceremony, "The tech community can take more responsibility for what's happening because we've been given so much, we have the opportunity to give back at scale as well."
If the fog obscured your view on Tuesday, most nights the Salesforce Tower will be hard to miss.