During the May Day holidays, Beijing is at its most inviting. Parks fill up, greenways hum with people, and spring seems to hit its stride. Yet for many residents, the season brings something else along with the sun and fresh leaves: fine white fluff drifting through the air.

It spins in loose swirls, slips into collars, sticks to camera lenses, and floats through the half-open window of ride-hailing driver Yang Shuquan's car. "Here we go again," he says, brushing it away with a wave of his hand. "Like snow that just hangs around."

From late April into May, as much of the country settles into spring, cities across northern China enter what locals half-jokingly call a season of "spring snow" — the airborne seeds of poplar and willow trees. The phenomenon can last for more than a month.

Yang has been driving in Beijing for years and knows this stretch well. "It's the toughest time of the year," he says. "You can't really open the windows. Once it gets in, your eyes sting, your throat feels off. After a while, it gets on your nerves."

He's hardly alone in this predicament. As temperatures climb, many northern regions move into peak fluff season. Data from the Beijing Municipal Forestry and Parks Bureau show that in 2026, the first wave began on April 6 and is expected to run through late May, roughly 50 days in total. The May Day holidays fall right in the middle of a second surge.