The polar vortex is forecast to settle near Hudson Bay, sending repeated waves of Arctic air into the central and eastern U.S. during the first half of December 2025.
Volcanic activity at Puracé, Colombia, intensified on November 30, 2025, prompting authorities to raise the alert level to Orange for the Los Coconucos volcanic chain in Cauca Department on December 1. Since then, continuous tremor, long-period seismicity, and sustained gas-and-ash emissions have been recorded, with columns exceeding 700 m (2 300 feet) above the summit (4 650 m / 15 260 a.s.l.) and occasional ashfall reported in nearby communities.
Downtown San Francisco reached only 10°C (50°F) on Sunday, November 30, 2025 – the city’s lowest daily maximum for the date in records dating back to 1874. The unseasonably cold conditions developed under a persistent marine layer and stagnant air pattern, keeping the city unusually cold for late autumn.
An Ice Storm Warning is in effect for the Kuskokwim Delta and Valley in Alaska through till 09:00 AKST on Wednesday, December 3, 2025. Heavy snow, Ice accumulations, and strong winds will create dangerous travel conditions and less than 400 m (0.25 miles) of visibility on roads due to blizzard conditions.
At least one person was injured after a tornado struck a motor camp near Lake Dudding in rural Manawatū on Wednesday afternoon (LT), December 3, 2025.
The season’s first nor’easter began impacting the Mid-Atlantic and Northeast overnight, prompting a State of Emergency in parts of New Jersey and school closures across multiple states. The storm is forecast to rapidly intensify, possibly dropping up to 30 cm (12 inches) of snow across parts of the interior Northeast through Tuesday.
Over 1 000 people have died and hundreds remain missing on Tuesday, December 2, 2025, after rare Tropical Cyclone Senyar brought severe flooding and landslides across Indonesia, Thailand, and Malaysia.
A landslide struck the river port of Iparia on the Ucayali River in central Peru’s Amazon region at dawn on December 1, 2025, submerging two passenger boats and killing at least 12 people, including three children. Dozens remain missing, while rescue efforts by local police and navy units continue under difficult river conditions.
At least 355 people were confirmed dead, and 366 remain missing as of December 1, 2025, after Cyclone Ditwah brought days of intense rainfall across Sri Lanka, producing severe flooding and landslides in multiple districts.
The National Weather Service has issued widespread winter weather advisories across the northern Rockies, Great Plains, Midwest, and eastern United States, with snow, blowing snow, and ice expected through Tuesday, December 2, 2025.
