Delhi-NCR residents are waking up to the first perceptible bite of winter this season, as mornings and evenings turn noticeably cooler following the monsoon's withdrawal from North India. Compounding the seasonal shift, the national capital's air quality is set to slip into the 'poor' category for the first time in 2026 by Monday, 20 October, according to pollution monitoring data.

Temperature Outlook for Delhi-NCR

The India Meteorological Department (IMD) has forecast mainly clear skies and dry weather over Delhi for the coming week, with no rainfall expected through at least 24 October. Minimum temperatures are projected to hover between 18 and 20 degrees Celsius, while maximums are likely to range from 31 to 35 degrees Celsius.

The Safdarjung Meteorological Centre recorded a maximum temperature of 31.7°C and a minimum of 18.6°C on 18 October — the maximum registering slightly below the seasonal average. Across neighbouring states including Uttar Pradesh, Punjab, Haryana, Bihar and Rajasthan, temperatures may remain up to two degrees above normal in some pockets during this period. A gradual but steady drift toward winter conditions is expected in the weeks ahead, though intense cold is not imminent.

Air Quality Deterioration

The Air Quality Index (AQI) in Delhi stood at 187 on Sunday — at the upper end of the 'moderate' band — but 22 monitoring stations across the city had already recorded 'poor' readings, signalling that pollution levels were elevated well before the city-wide average crossed the threshold.

The principal driver of the expected slide is meteorological: the absence of rainfall and relatively stagnant wind conditions reduce the atmosphere's ability to disperse pollutants. Emissions from vehicles, construction activity and other persistent sources continue to accumulate under these conditions. This pattern is consistent with the annual October–November deterioration that Delhi-NCR experiences as the monsoon retreats and crop-residue burning in neighbouring states begins to add to the pollution load.

Southern India: Heavy Rainfall Continues

The country's weather map presents a sharp contrast. The IMD has forecast an extended spell of heavy rainfall across southern peninsular India through 23 October. Tamil Nadu, Puducherry, Kerala, Karnataka and Lakshadweep are all expected to receive significant rainfall over the coming days, with isolated heavy showers likely in Tamil Nadu and Puducherry and heavy rainfall forecast for Kerala, Mahe and south interior Karnataka through 23 October. Coastal Andhra Pradesh and Rayalaseema were also forecast to receive heavy showers on Sunday.

El Niño Watch

Meteorologists have flagged the potential influence of El Niño conditions on the approaching winter season. Changes in Pacific Ocean temperatures could affect weather patterns across India, though the precise impact on winter temperatures and rainfall distribution remains uncertain at this stage. Historically, El Niño has been associated with below-normal monsoon rainfall in parts of India during affected seasons, but its effects vary considerably across years and regions.

What to Expect in the Coming Weeks

For Delhi-NCR, the transition is now clearly underway: dry, cool mornings will become increasingly common, and air quality is likely to worsen progressively as winter deepens. Authorities and residents should brace for more frequent 'poor' and potentially 'very poor' AQI days as October gives way to November. The seasonal air quality crisis — a recurring pressure point for the capital — is, by all indications, beginning on schedule.