Delhi air quality monitors had major gaps in October
In October 2025, Delhi's air quality monitors had major gaps in PM2.5 pollution data, including on Diwali night when pollution usually spikes.
Not a single station managed to record uninterrupted pollution levels all month, raising real worries about how well the city can track and respond to its air crisis.
Diwali night data blackout
On Diwali night, 28 out of 39 monitoring stations stopped reporting after midnight.
Chandni Chowk lost over nine days' worth of data, and Punjabi Bagh and Najafgarh each missed more than 100 hours.
A few spots like Anand Vihar saw fewer gaps—but overall, the city was flying blind during peak pollution.
Sensor failures, not just glitches
Experts say these long outages point to serious sensor failures—not just glitches—which means Delhi's actual air quality was probably worse than what got reported.
With residents already losing years off their lives from toxic air, reliable PM2.5 tracking is crucial for public warnings and emergency action plans.
Missing data makes it even harder to protect people's health when they need it most.