New Delhi endured another bitterly cold night on Friday, with temperatures plunging well below seasonal averages even as the capital's air pollution levels climbed deeper into the 'very poor' category.
Frigid Temperatures and Deteriorating Air
The city's minimum temperature settled at 5.6 degrees Celsius, marking a significant departure of four degrees below the normal range for this time of year. This matches the chill experienced on Thursday. Concurrently, the air quality index (AQI) deteriorated, registering 327 at 4 PM, a step down from Thursday's reading of 304, firmly placing it within the 'very poor' bracket according to monitoring agencies.
Weekend Weather Shift and Forecast
The India Meteorological Department (IMD) has forecast a rise in nighttime temperatures over the coming weekend. This change is attributed to an approaching western disturbance, which is expected to bring partially cloudy skies to the region.
The forecast indicates the minimum temperature will hover between 7 and 9 degrees Celsius on Saturday, and climb further to between 8 and 10 degrees on Sunday and Monday. Furthermore, wind speeds are predicted to pick up during the daytime on Saturday, reaching around 15-20 kilometers per hour, which may offer some temporary dispersion of pollutants.
Cold Wave Context and Historical Data
This December began with the coldest start since 2011, recording a low of 5.7 degrees Celsius. While the IMD had earlier forecast isolated cold wave conditions, only one station, Ridge, met the official criterion on Friday. For a cold wave to be declared, the minimum temperature must be below 10 degrees Celsius and also be at least 4.5 degrees below normal. This condition must be met by at least two stations for two consecutive days.
Typically, Delhi's coldest minimum temperatures below 5 degrees Celsius occur in the second half of December. Historical data reveals the lowest minimums in recent years: 4.5°C in December 2023, 5°C in 2022, 3.2°C in 2021, 3.1°C in 2020, and 2.4°C in 2019. By this time last year, the lowest recorded was 8 degrees Celsius.
Despite the anticipated stronger winds over the weekend, the Air Quality Early Warning System for Delhi indicates that the AQI is likely to remain in the 'very poor' category until at least Monday, offering little respite to residents from the hazardous air.
