Swallows linger longer in the cold north. Lotus flowers that usually fade by late summer are still in bloom. Osmanthus, a hallmark of autumn in southern China, hesitates to blossom.

Driven by climate change, China’s autumn started later this year, with summer lasting longer and winter starting earlier, disrupting the signals plants and animals usually rely on to sense the change in seasons.

Over the past week, hashtags such as “fast-forward autumn” and “skipping autumn, straight into winter” have been trending on Chinese microblogging platform Weibo.

This past summer was China’s hottest since records began in 1961, including several long-lasting heatwaves. In Shanghai, summer started on May 12 and ended on Oct. 19, lasting 160 days in total and 24 days longer than the average between 1991 and 2020.

In China, seasons are defined as having officially “begun” when specific temperature ranges — for example, greater than or equal to 22 degrees Celsius for summer — are met for five consecutive days.

As summer lingers, autumn in 15 major Chinese cities this year was delayed by an average of 9.4 days, compared with the 1991–2020 average, according to a data analysis by Shanghai-based media outlet The Paper. In Shanghai, as well as the nearby cities of Ningbo and Hangzhou in eastern Zhejiang province, autumn was delayed by up to 17 days.

In Ningbo, cherry blossoms that usually bloom in spring are budding again, lotus flowers remain open, and osmanthus trees — whose fragrant blossoms should have swept the city by now — remain dormant.

“This year’s summer lasted too long. The heat never really went away, so plants didn’t get the ‘cool-down’ signal they rely on. They thought spring had returned,” said a staff member from a local Ningbo landscaping bureau.

Then, starting Oct. 15, a cold wave swept across China, bringing a “cliff-like” drop of up to 16 degrees Celsius in temperature nationwide and triggering an unusually early onset of winter in northern provinces.

With the abrupt arrival of winter in the north, many swallows that should have already begun their migration toward warmer southern regions were unable to leave in time.

On Oct. 21, the hashtag “swallows staying behind instead of flying south” topped the list of trending topics on Weibo after approximately 100 of the migratory birds were filmed gathering to keep warm in front of residential buildings in China’s northeastern Heilongjiang province. Some reportedly froze to death.

Commenting on the videos, a staff member from the local forestry and grassland bureau told domestic media: “The temperature dropped sharply in recent days. Younger birds that couldn’t migrate in time froze to death, but adult swallows have left.”

Global warming is increasingly distorting China’s climate calendar. Data from the China Meteorological Administration show that since 1991, autumn has arrived progressively later across much of the country.

Last year, the delay of autumn also drew public attention. Osmanthus trees in the Shanghai Botanical Garden bloomed later than ever recorded, approximately two to three weeks after their usual flowering season.

“Extreme weather is like a ‘chain explosion’: first it messes up animals’ migration patterns, then it throws plants’ growth cycles into chaos, and eventually it hits human beings,” wrote one netizen. “The swallows’ predicament is a reminder: once nature’s systems fall out of balance, no one gets to remain untouched.”

Editor: Marianne Gunnarsson.

(Header image: VCG)