Overview
- Red warnings in Uttar Pradesh flag very dense fog with visibility below 50 metres across dozens of districts including Ayodhya, Prayagraj, Varanasi and Bareilly.
- Orange alerts extend to other Uttar Pradesh districts and several in Bihar such as Patna, Muzaffarpur and East and West Champaran for 50–200 metre visibility.
- IMD reported dense to very dense fog at multiple airports with visibility under 200 metres between 07:00 and 07:30 IST on December 26.
- The advisory, part of the December 25–31 outlook, projects isolated pockets of dense fog through late December, including Bihar in some areas until December 31.
- Meteorological drivers cited include lower-tropospheric cyclonic circulations, a strong subtropical westerly jet over Northeast India, and a feeble Western Disturbance set to affect the Western Himalayas from December 27.