Delhi woke up to biting cold and choking smog as the city’s air quality slipped back into the ‘severe’ category while temperatures dipped to 9.7 degrees Celsius, 4.5 notches below normal, making it the coldest November day in three years in the city.
This was the coldest day in the month since November 29, 2022, when Delhi registered 7.3 degrees Celsius. In 2023, the mercury levels were lowest on November 23 at 9.2 degrees, and in 2024, 9.5 degrees recorded on November 29 was the coldest day.
According to the India Meteorological Department (IMD), this is the first time the minimum temperature in Delhi has gone below the 10 degrees Celsius mark during this year’s winter season. On Saturday, the maximum temperature recorded in the capital was 26.6 degrees Celsius, which is also 1.9 degrees Celsius below normal for the season.
IMD has predicted shallow fog on Monday, with the maximum and minimum temperatures expected to settle around 25 and 9 degrees Celsius, respectively. For the next five days as well, the IMD has predicted Delhi’s minimum temperature to swing between 8-12 degrees Celsius and maximum temperature between 23-27 degrees Celsius.
The air quality remained ‘very poor’ on Sunday, with the 24-hour average Air Quality Index (AQI) at 377. However, in some areas such as Anand Vihar, Chandni Chowk, ITO, and Bawana, the air turned ‘severe’ as well with AQI of 412, 418, 417, and 436, respectively. According to CPCB’s Sameer app, 11 of the 39 monitoring stations reported AQI levels in the ‘severe’ category, with readings above 400.
Delhi’s air remained ‘very poor’ on Saturday as well with an AQI of 386. On Friday too, the air was in the ‘very poor’ category, which is a slight improvement from earlier days during the week when Delhi’s air turned ‘severe’.
The centre’s Early Warning System (EWS) projected, “Ventilation index is likely to be 1,500 m²/s on Nov 17, and 3,000 m²/s on Nov 18 over Delhi. A ventilation index below 6,000 m²/s with average wind speeds under 10 km/h is unfavourable for dispersing pollutants.
Air quality is expected to be severe from Nov 17-18. Last November, Delhi recorded eight severe air days, peaking at an AQI of 494 on Nov 18, 2023—the second-highest on record. Historical data shows November has repeatedly brought hazardous air episodes in the capital, including nine severe days in 2023, 11 in 2021 and 10 in 2016.
As per CPCB, an AQI between 0 and 50 is considered ‘good,’ 51-100 ‘satisfactory,’ 101-200 ‘moderate,’ 201-300 ‘poor,’ 301-400 ‘very poor,’ and 401-500 ‘severe.’ Tiny airborne particles such as PM2.5 and PM10 remained the dominant pollutants.