Delhi is likely to receive light rainfall on Friday that would further dip the minimum temperature in the national capital to 5 degrees Celsius, predicted the India Meteorological Department. On Thursday, the city recorded a minimum temperature of 6.4 degrees Celsius, two notches below the season’s average.
The mercury recorded a high of 23 degrees Celsius, a notch above normal, according to the IMD weather bulletin. The relative humidity at 5.30 pm was at 64 per cent, the bulletin said.
In terms of air quality, the 24-hour average Air Quality Index (AQI) remained in the ‘very poor’ category at 361, the data from the Central Pollution Control Board show.
The data showed the contribution of vehicles to PM2.5 concentration was 35% on Thursday at 5 pm while the contribution of biomass burning was 34%. Burning of plastic and waste contributed another 6%. It also showed the previous day’s contribution at the same time as 61% from vehicles, 20% from biomass burning and 1% from waste burning.
Biomass burning includes burning of firewood, dung and leaves in the open — a common occurrence in winters, when temperatures start to dip at night. Earlier this week, rampant instances of biomass burning were flagged by the Delhi Pollution Control Committee to the Municipal Corporation of Delhi. In a letter on Tuesday to MCD, DPCC flagged 43 hot spots across the city, where biomass burning has been detected regularly over the last year.
Forecasts show Delhi’s air quality would remain “very poor” over the next three days.
“Delhi’s air quality is likely to remain in the ‘very poor’ category from December 22 to December 24. The outlook for the subsequent six days shows the air quality is likely to remain between ‘very poor’ and ‘poor’,” said the Early Warning System (EWS) for Delhi, a forecasting model under the ministry of earth sciences.
An AQI between zero and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and 401 and 500 ‘severe’.