New Delhi experienced a brief respite from its notorious winter smog on Friday, as strong surface winds significantly improved air quality across the Capital. After days of hazardous pollution levels, the city’s Air Quality Index (AQI) dropped dramatically, providing relief to residents, even as authorities caution that the improvement may be temporary.

As of Saturday morning, Delhi’s air quality stood at 235, placing it in the ‘poor’ category, according to the Central Pollution Control Board (CPCB). This was slightly below the 24-hour average AQI of 236 recorded at 4 pm on Friday. The improvement came after the AQI had touched 380 (very poor) on Thursday afternoon, prompting intense public concern. The sudden relief was largely attributed to strong northwesterly surface winds, which dispersed pollutants and improved air circulation across the region.

---

Impact on Regulatory Measures

The improvement in air quality allowed the Commission for Air Quality Management (CAQM) to lift stage-3 measures under the Graded Response Action Plan (GRAP) in the National Capital Region (NCR) on Friday evening. Stage-3 restrictions, typically enforced when AQI levels exceed 400, include curbs on construction activities, industrial emissions, and vehicular restrictions in Delhi and surrounding areas. With AQI levels dropping below 300, authorities were able to ease these measures temporarily, offering relief to commuters and industries alike.

However, meteorological forecasts indicate that the relief may be short-lived. According to the Air Quality Early Warning System (AQEWS) for Delhi, air pollution is likely to worsen over the coming days:

• Saturday: AQI likely to remain in the poor category.
• Sunday to Monday: AQI forecast to reach the very poor category.
• Next six days: Air quality expected to remain in the very poor range, signaling a prolonged period of unhealthy conditions.

CPCB guidelines classify air quality as:

• Moderate: AQI 101–200
• Poor: AQI 201–300
• Very Poor: AQI 301–400
• Severe: AQI above 400

For GRAP purposes, stage-3 measures are triggered when AQI forecasts exceed 400, while stage-4 restrictions may be imposed if AQI crosses 450.

---

Weather Conditions and Temperature Trends

The temporary improvement in air quality is closely linked to the prevailing cold northwesterly winds, which have swept across Delhi and the surrounding plains. While the winds have helped disperse particulate matter, they have also led to a drop in minimum temperatures across the region.

• Saturday minimum temperature: 8.1°C (1.2°C above normal, but lower than Friday)
• Forecasted minimum: Expected to dip to 6–8°C over the weekend
• Maximum temperature: Hovered around 17.4°C on Friday, expected to remain between 17–19°C on Saturday

The India Meteorological Department (IMD) has issued a yellow alert for Sunday, warning of moderate fog persisting in the late evening hours, which could impact visibility and travel.

---

Impact on Air Travel

Poor weather conditions have already had a visible impact on air travel. According to FlightRadar24, at least 150 flight delays were recorded at Delhi’s Indira Gandhi International Airport on Saturday morning. Airport officials noted that the delays were primarily caused by reduced visibility at other airports across North India, including major hubs where fog levels fell to near zero.

The IMD has forecasted dense to very dense fog conditions to continue across Punjab, Haryana, Chandigarh, Uttar Pradesh, Bihar, and Odisha for the next 5–7 days, while parts of Jammu, Himachal Pradesh, Uttarakhand, Rajasthan, north Madhya Pradesh, and Northeast India can also expect foggy conditions over the next 4–5 days. This persistent fog, combined with urban emissions, is likely to contribute to a deterioration in air quality despite the temporary improvement brought by the winds.

---

Health Implications and Public Advisory

While the temporary drop in AQI to 235 offers some relief, the levels remain harmful for sensitive groups, including children, the elderly, and individuals with respiratory conditions. Authorities continue to advise:

• Limiting outdoor activities during early morning and late evening hours
• Wearing protective masks if traveling in polluted areas
• Using air purifiers at home or in offices
• Following government advisories for travel and industrial activity

Experts caution that the brief improvement is not indicative of a long-term trend, and residents should remain vigilant as weather conditions shift, potentially causing air quality to plunge back into the very poor range.

---

Conclusion

Delhi’s air quality saw a notable improvement on Friday due to strong surface winds, bringing the AQI down from hazardous levels. However, forecasts indicate that the city will continue to grapple with poor to very poor air qualityover the next week, exacerbated by dense fog and cold northwesterly winds across northern India.

Authorities, including the CPCB, CAQM, and IMD, are monitoring conditions closely, ready to implement GRAP measures if necessary, while citizens are advised to take preventive health precautions. The situation underscores the seasonal vulnerability of Delhi and NCR to winter pollution, highlighting the complex interplay between weather, human activity, and urban air quality.

---