Delhi-NCR wakes to dense fog on Jan 2; CSE says winter smog is now mostly 'homegrown', not stubble smoke

IMD flags dense fog, temperatures dip to 8–10°C; a new CSE analysis says PM2.5 rose in December even as stubble smoke faded

• Delhi-NCR saw dense fog and poor visibility, affecting flights and travel plans
• PM2.5 pollution rose in December despite fewer farm fires, local sources blamed
• Delhi govt: 2025 had best air quality in 8 years with more good AQI days

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Delhi-NCR began January 2 with partly cloudy skies and moderate fog in many areas, turning dense to very dense in pockets, as the India Meteorological Department (IMD) warned of poor visibility through the morning.

The cold is also tightening its grip. IMD’s forecast pegs Friday’s temperatures at 16–18°C (max) and 8–10°C (min), after Thursday’s reading hovered around 17.3°C (max) and 10.6°C (min).

Fog hits travel plans; airlines warn of disruptions

The fog is already spilling into the airport story. Flight operations in Delhi have faced delays and cancellations during the New Year fog spell, and airlines have issued advisories and cancellations to manage passenger load and waiting times.

IndiGo, for instance, said it had cancelled some flights in advance amid low visibility conditions, asking passengers to check updates and offering assistance at the airport.

The bigger worry: winter smog rising even without farm fires

Here’s the uncomfortable twist: even as farm fires dropped to negligible levels in December, Delhi’s particulate pollution rose.

A new analysis by the Centre for Science and Environment (CSE) found that average PM2.5 concentrations were higher in December than in October–November, despite the farm-fire contribution falling sharply. The implication is blunt: local and regional sources, vehicles, industry, waste burning and household fuels, are doing most of the damage in core winter.

CSE’s point is not “stubble doesn’t matter.” It’s that when stubble stops, Delhi doesn’t clear—it often gets worse, because the city’s own emissions meet cold air, weak winds and inversion-like winter conditions.

Delhi govt says 2025 was the “best AQI in eight years”

In parallel, Delhi’s government has claimed it made measurable gains in 2025, citing more “good AQI” days and fewer extreme pollution episodes. Environment Minister Manjinder Singh Sirsa has pitched 2025 as Delhi’s best air quality stretch in eight years, crediting tighter enforcement across dust, vehicles, industry and waste.