Delhi faced its worst December air pollution since 2018 in 2025, with PM2.5 averaging 211 µg/m³ for the month. Data from the Central Pollution Control Board shows high pollution levels affected nearly all monitoring stations across the city. Experts attribute this not just to weather but to persistent year-round emissions.
Delhi's average PM2.5 level in December 2025 stood at 211 micrograms per cubic meter, the highest since 2018. Data from the Central Pollution Control Board (CPCB) across 40 monitoring stations indicates that high pollution affected nearly every location at least once. One in three days saw citywide PM2.5 exceed 250 micrograms per cubic meter, with a mid-December episode pushing levels to six or seven times the national standard.
This year's figure marks a rise of over 40 micrograms per cubic meter compared to 2024, despite similar or slightly warmer temperatures. Manoj Kumar, pollution analyst at the Centre for Research on Energy and Clean Air (CREA), stated: "Delhi recorded its highest PM2.5 level (since December 2018) of 392 µg/m³ on December 14, 2025. The absence of stubble burning during this peak makes it evident that Delhi’s air pollution is also being driven by persistent, year-round emissions. This calls for enforceable, sector-specific emission reduction targets for industry, transport, power plants, and other major sources."
Sunil Dahiya, lead analyst at Envirocatalysts, noted: "This year recorded much lower average concentrations till October due to favourable meteorological conditions, but the baseline emissions in the region were so high that with the onset of winter, the same hazardous pollution levels were back." He added that efforts have failed to curb absolute emissions through cleaner technologies and a shift from fossil fuels.
Daily averages surpassed 250 micrograms for 31% of the month and 150 for over 82%. The peak was 392.65 micrograms on December 14, followed by 360.12 on December 13. Station variations ranged from 271.83 at Anand Vihar to 136.95 at NSIT Dwarka, all exceeding the national limit of 60. Mundka hit 597.67 on December 14—the highest single reading—roughly 35 to 40 times WHO safe levels.
Hourly data revealed peaks predominantly at night. This reversal follows relatively lower pollution in 2024.
