New Delhi has been gripped by an intense and early winter chill, with temperatures plummeting to levels not seen in the first week of December for at least fifteen years. The India Meteorological Department (IMD) reported that the national capital recorded a minimum temperature of 5.7 degrees Celsius on Monday, marking a significant drop of five degrees below the seasonal normal.
Record-Breaking Chill and IMD's Cold Wave Definition
This reading represents the coldest minimum temperature for the first week of December since reliable data tracking began in 2011. The IMD has forecast that this biting cold spell will continue, with the possibility of isolated cold wave conditions in parts of the city until at least Friday. According to the weather office, a cold wave is officially declared when the minimum temperature dips below 10 degrees Celsius and is also at least 4.5 degrees below the normal reading, with at least two weather stations meeting this criterion for two consecutive days.
IMD scientist Krishna Mishra clarified the current situation, stating, "As per data, the subdivision of Haryana-Chandigarh-Delhi reported departures below 4.4°C over at least two stations. Being the first day of reporting such departures, it will not be considered a cold wave day." However, Mishra warned that the mercury will remain below normal, with isolated cold waves likely for the next five days. Forecasts indicate the minimum temperature will swing between 5 and 9 degrees Celsius until Friday.
City-Wide Dip and Deteriorating Air Quality
The cold has enveloped the entire capital region. Following the base station at Safdarjung's 5.7°C, Lodhi Road recorded 5.8°C and Ayanagar 6.5°C. This represents a sharp decline of nearly five degrees since Saturday, when the minimum was 10.4°C, falling to 8.3°C on Sunday.
Simultaneously, the city's air quality has worsened again. After a brief respite in the 'poor' category due to the northwesterly winds, the air quality index (AQI) has re-entered the 'very poor' zone. The 24-hour average AQI stood at 304 at 4 pm on Monday, deteriorating from 279 on Sunday. The IMD predicts that the air quality will remain in the 'very poor' category until at least Thursday.
Historical Context of Delhi's December Winters
This early deep chill is unusual. While minimum temperatures typically fall below 5 degrees Celsius in December, it usually happens in the second half of the month. A look at recent years highlights the anomaly:
- In 2023, the lowest minimum in the first week was 9.2°C on Dec 7.
- In 2022, it was 7.6°C on Dec 5.
- In 2021, it was 11°C on Dec 4.
- In 2020, the earliest cold wave was recorded on Dec 19.
- Last year (2023), the lowest in the first week was 7.1°C on Dec 7.
The all-time record low for December in Delhi remains 0 degree Celsius on December 27, 1930. In recent history, the last December with cold wave days was 2021, which recorded four such days. Since 2011, the highest number of cold wave days in December was eight, recorded in 2018. The current trend suggests this winter is setting in with unprecedented early severity, combining intense cold with challenging air quality for Delhi's residents.
