When do tulips open their flowers more quickly?
On very warm days, tulips even open to the point where the petals overhang.
Botanists call this movement, triggered by temperature stimuli, "thermonasty." It is repeated dozens of times during the blooming period.
By the way, the blossoming of a tulip bud is also mainly dependent on temperature.
This is because when closed tulips are in water at about 30 degrees, they open their flowers much faster than in cold water.