Delhi’s Chill Eases, No Cold Wave Till Mid-December; AQI Slips to ‘Very Poor’
Key Takeaways:
- Delhi’s early-season chill has eased slightly, with minimum temperatures rising after several days below normal.
- Weak western disturbances have resulted in “dry cold” conditions, preventing a typical cold wave from developing.\
- Fog remains absent across Delhi, with pollution-driven haze dominating visibility and keeping AQI in the “very poor” range.
- No rainfall is expected till mid-December, and no cold wave is likely during this period, although chilly winds will persist.
Early Winter Chill & Pollution
Delhi’s first serious brush with winter has started to loosen its grip even as the city continues to choke on polluted air. After an extended spell of below-normal minimum temperatures through November and the first week of December, the last two days have brought a marginal rise in temperatures across Delhi-NCR. However, the early-morning air on Monday still fell in the “very poor” category, with the city’s average Air Quality Index (AQI) at 318 and no meaningful improvement in sight.
November itself had set the tone for an early winter chill. The month recorded a mean minimum temperature of 11.4°C against the normal of 13°C, a significant negative departure for the pre-peak winter phase. The first five days of December then doubled down on the pattern, with minimum temperatures slipping into the low single digits and staying 3°–4°C below normal. The season’s lowest of 5.6°C was logged on two consecutive days, keeping Delhi on the edge of cold wave criteria.
Through this stretch, mercury levels repeatedly “shied away” from meeting the threshold for a full-fledged cold wave, missing it by small margins. Now, as of December 8, minimum temperatures have inched up, reducing the intensity of the chill.
The moderation, however, is not strong enough to be called a warm-up, mornings and late evenings remain quite cold, especially under the influence of brisk northwesterly winds.
Western Disturbances, Dry Cold & Missing Fog
The broader synoptic setup continues to be shaped by the behaviour of western disturbances. Typically, extreme cold over the plains is an offshoot of strong western disturbances that dump heavy snow over the western Himalayas and trigger rain and thundershowers across the north Indian plains. Such systems stir the atmosphere, reset temperature profiles, and then pave the way for sharp post-system cooling.
lack of active western disturbances has left Delhi under a regime of “dry cold”—clear skies, low humidity and steady night-time cooling, but without the sharp post-rain plunge needed for a true cold wave. Adding to the unusual pattern, classic winter fog is missing, replaced by pollution-driven haze and only shallow fog instead of the typical dense December blanket.
Air Quality Status
Air quality, on the other hand, continues to be a serious concern. On Monday, Delhi woke up to very poor air, with an average AQI reading of 318. Data from the Central Pollution Control Board’s Sameer app showed 27 monitoring stations in the “very poor” category and 11 in the “poor” range. According to CPCB’s classification, an AQI of 301–400 is labelled “very poor” and is associated with respiratory discomfort on prolonged exposure, especially for sensitive groups such as children, the elderly, and those with pre-existing lung or heart disease. Despite the slight rise in temperature, the pollution load has not eased, indicating that the current meteorological conditions are still not favourable enough to disperse accumulated pollutants.
Forecast:
Rainfall is likely to remain absent till mid-December, keeping humidity too low for dense fog and allowing pollutants to linger. Slightly stronger winds will maintain the chill, even without a sharp drop in minimum temperatures.
Looking ahead, minimum temperatures over Delhi-NCR are expected to hover near or slightly below normal, without a sharp fall or notable spike over the next week. As things stand, there is no clear signal of a full-fledged cold wave over the region till about mid-December. The city is, for now, stuck in a hybrid winter mode, less brutal in terms of temperature, but harsh in terms of the air its residents are breathing.
Must Read: From Belém to Bharat: How COP30 Reframed Climate Action and India’s Adaptation Priorities
