Brrrr! It's chilly out there! With a sudden drop in temperature over recent days that has cruelly shortened the city’s already brief fall season, winter has officially made its arrival in Beijing. But what has caused this rapid temperature decline? How uncommon is this for Beijing? What can you do to cope with the winter cold? And, perhaps most importantly, will heating be activated early this year?
Beijing Experiences an Early Winter
Temperatures in and around the capital have recently dropped significantly, with average highs now in the low to mid-teens, compared to the previous lows in the low twenties. Daytime temperatures are expected to remain firmly in the teens for about the next month, while nighttime readings will consistently be in the single digits, nearing freezing yet anticipated to hover above that mark until mid-November.
The National Meteorological Center (NMC) of the China Meteorological Association (CMA) reports that a strong cold front from the north has greatly decreased temperatures throughout the region. From October 18 to October 24, Beijing's daily average temperatures are expected to stay below 10 degrees Celsius for seven consecutive days. This, along with other measured meteorological factors, suggests that winter may have already begun in Beijing as of October 18.
Between 1991 and 2020, the average start date for winter in Beijing was October 31. Thus, the estimated October 18 start date this year indicates that winter has commenced approximately two weeks earlier. However, this is not completely unusual; previous early winter dates for Beijing include October 16 in 2021, October 17 in 1964 and 1986, and another October 18 in 2002.
What’s Causing This?
The recent abrupt change in weather is likely attributed to a combination of several meteorological phenomena, according to Renmingwang (People's Daily). Some of the likely contributing factors include:
The Arctic Vortex shifts downward: The Arctic Vortex, a powerful low-pressure system surrounding the Arctic, generally traps polar cold air in high latitude areas. However, in October this year, due to sudden stratospheric warming, the vortex experienced abnormal splitting and instability, leading to a significant southward "leak" of cold air. This unusual circulation pattern has resulted in frequent cold waves impacting mid-latitude regions (including northern China), causing a rapid cooling effect.
Unusually enhanced Siberian high pressure: Siberian high pressure serves as a "cold reservoir" for the Asian continent’s winter and has strengthened ahead of schedule this year. Since October, this high-pressure system has continued to accumulate cold air, generating a robust air pressure gradient. When the system shifts southward, the cold air bursts forth, leading to severe cooling in northern China.
Direct access to cold air: The northern regions of China feature open land without significant east-west mountain barriers, allowing cold air from Siberia to flow directly in through three primary routes: the northwest pathway from Xinjiang and the Hexi Corridor, a direct south route from the Mongolian plateau, and the eastern route entering from the northeastern plains.
La Niña's potential influence: Currently, sea surface temperatures are low in the equatorial Middle East and Pacific Ocean, which aligns with La Niña's development. Though not yet fully formed, La Niña's moderating effects on the overall atmospheric circulation may already be influencing increased cold air activities.
Arctic amplification effect: Polar warming weakens or distorts the polar vortex, making it more likely for cold air to push into mid-latitudes. Therefore, despite overall global warming trends, extreme cold wave events may become more pronounced, leading to "cold anomalies within a warmer context."
Winter Weather Across the Nation
Beijing is certainly not the only place in the country experiencing this chilly weather. Northern regions like Inner Mongolia, Heilongjiang, and Jilin have already seen significant snowfall, with reports indicating that some outlying districts of Beijing may also expect snow.
As the cold air shifts south in the coming days, much of southern China, which has recently been rain-soaked, is expected to remain rainy, with temperatures continuing to drop, leading to frost in some western areas. Persistent rainfall may lead to secondary natural disasters, such as flash floods and landslides.
Does an Early Winter Indicate Early Heating?
We still have nearly a month until the legal heating period in Beijing, which is from November 15 to March 15. If the city’s average temperature stays below 5 degrees Celsius for five consecutive days, city officials will decide whether to initiate early heating. So, we will have to wait and see...
Does an Early Winter Mean an Extra-Cold Winter?
Not necessarily. The timing of winter's arrival and the overall coldness of the winter season are two separate matters, and they are not inherently linked.
Whether winter arrives early or late reflects temperature variations during the seasonal transition, while determining a "cold" winter assesses whether the average temperature throughout the winter season
Winter has come early to the capital.