Beijing — NDJ 2025/26 Aerolight

Overview of expected weather for Nov–Dec–Jan 2025/26: polar vortex effects, jet stream roles, moisture sources (Yellow Sea, Bohai), snow/freezing rain mechanics, transport & health Effects, and regional terrain influences.

Executive Summary

Late 2025 into early 2026 is expected to feature an active Eurasian winter pattern with frequent cold surges into northern China driven by a strong polar/Eurasian vortex and wavier jet stream. Beijing will see repeated freezing nights, cold daytime spells during surges, and episodic precipitation events (snow or freezing rain) when maritime moisture from the Yellow Sea/Bohai is advected inland by coastal lows. Overall, expect colder-than-autumn conditions, increased frost/ice risk, and intermittent transport Effects during major events.

Physical Drivers & How They Interact

Eurasian Polar Vortex & Cold Pool

The Eurasian polar vortex and the Siberian high build in autumn/winter. When strong and coupled to tropospheric flow, the vortex extends cold air reservoirs over Siberia and Mongolia, enabling deep cold surges that push south into northern China and Beijing. These surges produce the coldest nights and fuel high-pressure outbreaks across the North China Plain.

Jet Streams (Polar jet & STJ)

Deep troughs in the polar jet create pathways for Arctic/Siberian air to plunge southeast. The subtropical jet modifies storm tracks: a southward STJ favors coastal cyclogenesis and moisture transfer from the Pacific and Yellow Sea; a northward STJ reduces coastal storms, leaving drier and colder conditions over Beijing.

Cold Nights vs. Winter Days

After a cold surge, clear skies and light winds lead to strong radiational cooling—producing severe overnight freezes and frost. Daytime temperatures remain cold but can be moderated by cloud cover during moisture intrusions. Expect large diurnal ranges: very cold nights and modestly cold days, unless clouds limit daytime warming.

Moisture Sources: Yellow Sea, Bohai, and Bay of Japan

The Yellow Sea and Bohai are Beijing’s primary nearby moisture sources. When a coastal or offshore low pulls warmer maritime air inland over the cooler continental surface, precipitation develops. If the cold layer near the ground is shallow, freezing rain results; if the cold column is deep, precipitation falls as snow. East‑west interactions with the Bay of Japan are less direct for Beijing but can influence larger-scale storm tracks that help develop coastal lows.

Snow, Freezing Rain, Frost & Ice — What to Expect

  • Snow: requires a sufficiently cold vertical column, moisture from the Yellow Sea/Bohai, and lift from fronts or coastal lows. Best chance in Dec–Jan.
  • Freezing rain: occurs when warm air aloft melts precipitation that refreezes on contact with a cold surface layer—typical near warm fronts or when maritime air undercuts shallow cold air.
  • Frost/Black ice: follow clear, calm nights after surges—major hazard on roads and bridges.

Terrain & Regional Influences

Mountains north and northwest of Beijing enhance orographic cooling and precipitation on windward slopes, and they can channel or block flows. The Mongolian plateau and SW Mongolia amplify cold outbreaks that funnel into northern China. Provinces south/west of Beijing—Shanxi, Hebei, and Shandong—act as corridors for moisture or as barriers shaping frontal progression; Shandong and the Yellow-Sea corridor are especially important when determining whether a coastal low will tap enough moisture to impact Beijing.

Transport & Infrastructure Risks

Heavy snow, freezing rain and black ice threaten road, rail and air operations. Freezing rain is especially disruptive—causing power line icing, tree damage, and immediate hazard to road users. Rapid snowbands can close highways and delay trains. Authorities should prepare pre-treatment strategies for major routes and contingency plans for airports during storm events.

Health & Public Safety

Cold stress increases cardiovascular strain and raises incidence of respiratory infections. Vulnerable populations (elderly, young children, people with chronic illness, homeless) face higher risk. Public health measures include ensuring heating access, warming shelters, targeted outreach, and preparedness for increased hospital and ambulance demand during prolonged cold spells.

NDJ 2025/26 Time-Window Expectations

MonthPrimary weather tendenciesHazards
November 2025Transition to winter; early strong cold pulses; first frosts and light snow/freezing rain possibleFrost, localized freezing rain
December 2025Frequent cold surges; higher snow probability if coastal lows form; more persistent sub-zero nightsSnow accumulations, freezing rain, transport disruption
January 2026Coldest month; peak potential for extended sub-zero periods and impactful snow events when moisture presentProlonged cold, snow/ice Effects, energy & health stress

Monitoring & Preparedness Checklist

Authorities: monitor Siberian high strength, jet stream troughs, coastal low formation near Bohai/Yellow Sea, and SSTs for sea‑effect potential; pre-treat critical highways and rail links.
Transport operators: prepare de-icing, grit, and contingency schedules for airports and rail; communicate early delays to the public.
Public & households: winterize heating systems, prepare emergency kits, check on vulnerable neighbors, avoid travel during severe freezing‑rain or heavy‑snow warnings.