The Chicago Pride Parade has been cancelled due to inclement weather.— Chicago Police (@Chicago_Police) June 30, 2019
Authorities called the parade off about 30 minutes before it was scheduled to end.
The Chicago Office of Emergency Management told Pride Parade-goers to seek shelter immediately the National Weather Service issued several storm warnings.
A Severe Thunderstorm Watch is in effect until 6 p.m. for parts of northern Illinois including Cook, DuPage, Ford, Iroquois, Kankakee, Kendall, Livingston and Will counties.
A Severe Thunderstorm Watch was also in effect until 3:30 p.m. in La Salle County.
Severe weather is also expected later Sunday, between 8 p.m.-1 a.m.
CLICK HERE for the latest 7-day outlook from the First Alert Weather Team:
Pride Parade Update: Thunderstorm approaching. Seek shelter immediately.— Chicago OEMC (@ChicagoOEMC) June 30, 2019
Officials were on site directing parade-goers to public transportation.
Before the storms, Mayor Lori Lightfoot led the festivities as a grand marshal while there were still clear skies and sunshine. She's Chicago's first openly gay mayor and walked alongside her wife, Amy Eshleman, to cheers from the crowds.
"I feel honored and humbled to be serving as the grand marshal of this great celebration of pride and diversity and inclusion in our city," Lightfoot said. "It shouldn't matter who you love to be a part of this great city. So as long as I am mayor, I am going to do everything I can to make our city welcoming."
Sunday's parade marked the 50th anniversary of the Stonewall Riots, which sparked the modern-day gay rights movement.
RELATED: Stonewall Riots, 50 years later
Parade goer Pam Wolff was a toddler when Stonewall happened.
"It's so great to be out here, especially with such division in this country to be united about civil rights, it's just a really powerful thing," she said.
The colorful celebration of love featured dozens of diverse organizations, including the ABC 7 Chicago team. Hundreds of thousands lined the four-mile parade route to take in the sights.
"It's amazing. I have some hope because this government is scary but it's nice to have some love here. It feels great. I feel loved here," said parade goer Bella Auguinaga. She said she was moved to tears seeing Lightfoot lead the parade.
The Associated Press contributed to this report.