Archive · 3 Oct 2026
Delhi Begins October With Highest Pollution in Four Years
Delhi's air became more polluted as October began.
On October 1, its average air-quality score was 166, which is called moderate.
Some monitoring stations recorded worse air, including IIT Delhi, where the score was 248.
Rain had helped clear the air in September, when the monthly average score was 102.
After the rain stopped, pollution levels started rising.
Slow winds and poor ventilation made it harder for pollution to move away.
Forecasters expected air quality to stay moderate through October 4.
After that, it was expected to shift between moderate and satisfactory for several days.
Delhi's average AQI reached 166 on October 1, remaining in the moderate category.
CREA said the city has not had a more polluted October opening since 2022, when AQI reached 186.
Of 44 monitoring stations, 37 recorded moderate air quality, five poor, and two satisfactory.
IIT Delhi recorded the highest station-level AQI at 248, followed by Jahangirpuri at 218.
Low wind speeds and poor ventilation slowed pollution dispersal after September's rain-driven cleaner conditions.
- Who
- Delhi and its air-quality monitoring stations.
- What
- The city recorded an average AQI of 166, its most polluted start to October in four years.
- When
- October 1, 2026.
- Where
- Delhi, India.
- Why
- Subdued surface winds and poor atmospheric ventilation trapped pollutants; the article also notes that post-monsoon rain had stopped.
- October 1 average AQI
- 166, in the moderate category
- Previous higher October opening
- 2022, when AQI reached 186
- Monitoring stations
- 37 moderate, five poor, and two satisfactory out of 44 operational centres
- Highest station reading
- IIT Delhi: AQI 248
- September 2026 monthly average
- AQI 102, the cleanest September in five years
- Forecast
- Moderate through October 4, then moderate to satisfactory over the following six days