It’s been a rough month for fans of spring weather in China. On March 25, the Shanghai Xujiahui Observatory recorded temperatures exceeding 30°C, shattering the longstanding record for the earliest such occurrence since 1933. Historically, Shanghai’s first 30°C day would typically fall only in late April or early May.

Then, almost overnight, the heat was gone — replaced by a cold front that descended on much of China. According to the China Meteorological Administration, a cold wave lasting from March 24 to March 30 is expected to bring temperature drops exceeding 20°C to some regions. Northern China is expected to experience its lowest temperatures between March 27 and March 29, while southern China might see similar conditions between March 29 and March 30.

Looking at data from the past 74 years, record-breaking March heat has become the norm in some provincial capitals. However, rapid temperature drops of 20°C or more remain relatively rare.

Hotter days and wilder swings

Since the beginning of March, 20 Chinese provincial capitals — including Changsha in the central Hunan province, Hefei in the eastern Anhui province, and Zhengzhou in the central Henan province — have experienced a full year’s worth of weather compressed into a single month. From March 1 to March 24, daily highs oscillated dramatically, ranging from below 10°C to over 22°C.

Hefei saw the most dramatic single-day temperature shift, with the high on March 3 down more than 20°C from the previous day. A local news report explained that a strong cold front caused Hefei’s temperature to plummet from 28°C at 2 p.m. to 14.8°C just one hour later.

March has also brought extreme heat to much of the country. According to Weather China, over 300 national weather observatories were poised to break historical heat records this month. Observatories in Henan, Hubei, Hunan, Zhejiang, and the eastern Fujian provinces may even set new records for their earliest-ever 35°C days.

The trend toward warmer March weather is picking up steam. According to the past 74 years of meteorological data, several provincial capitals, including Lanzhou in the northwestern Gansu province and Shenyang in the northeastern Liaoning province, have set new March temperature records in the past three years.

Cooling off

As March draws to a close, many regions are bracing for a dramatic temperature plunge, with temperatures expected to drop by nearly 70%. According to Weather China, 11 provincial capitals are expected to see daily highs fall by more than 20°C this week. Cities such as Lanzhou, Guiyang in the southwestern Guizhou province, Yinchuan in the northwestern Ningxia Hui Autonomous Region, Xining in the northwestern Qinghai province, and Hefei all expect to see sharp 20°C drops within a 48-hour period.

Historically, such drastic 48-hour drops of over 20°C in March have been rare. Over the past 74 years, only Guiyang has recorded this phenomenon more than 10 times. Current forecasts suggest that Xining and Lanzhou may break their records for the most extreme 48-hour temperature drop this March.

Reported by Kong Jiaxing.

A version of this article originally appeared in The Paper. It has been translated and edited for brevity and clarity, and is republished here with permission.

Graphic designers: Wang Yasai and Fu Xiaofan; editors: Wang Juyi and Elise Mak.

(Header image: Visuals from VCG, reedited by Sixth Tone)