Gusts might range from 25 to 35 mph (40 to 56 kph) and early morning wind chill readings would be in the 30s, the National Weather Service said.
Under the theme "The Melody of Life," the parade of flower-covered floats, marching bands and equestrian units kicks off at 8 a.m. Tuesday with an opening performance that includes recording artist Chaka Khan, who is serving as parade grand marshal.
"This is all new for me," the 65-year-old Khan told The Associated Press recently. "I love challenges. And I love new stuff."
Also talking about an improbable role was the 101st Rose Queen, local high school senior Louise Deser Siskel, who wrote in an op-ed in the Los Angeles Times about how she would use the platform to advocate for science education, the importance of science informing public policy and the value of inclusion.
"Personally, I am happy to be the first Rose Queen to wear glasses on the float (even though they clash with the crown), and the first Rose Queen to talk about being Jewish. I feel an additional responsibility to myself and to this tradition, to share that I am bisexual," she wrote.
Siskel added that she felt it was important to present herself "authentically, especially to those who look to the Royal Court as a representation of our community."
Diversity has been a watchword for the Tournament of Roses Association, which organizes the parade, since it came under sharp criticism in the early 1990s as being a bastion of white men.
At float-building facilities in and around Pasadena, meanwhile, professionals and volunteers worked to complete finishing touches for the early morning rollout before fans in bleachers, on crowded sidewalks and those watching on TV.
"We're in the final push," said veteran designer Dave Pittman, who has two floats in the 2019 parade. "The weather was beautiful, which was great for the volunteers but tough on the flowers because they were blooming a little early."