New Delhi witnessed a significant and welcome improvement in its air quality on Saturday, marking a rare positive development for the capital's residents. The Air Quality Index (AQI) touched 192 at 4 PM, categorizing it as moderate. This reading represents the cleanest air Delhi has experienced in 102 days, with the last moderate AQI recorded on October 13 last year at 189.
Weather Factors Driving the Change
The improvement began on Friday, primarily driven by the influence of rain and gusty winds across the region. Despite this, the day's average AQI remained in the poor category at 282. The recent rainfall and fresh snowfall in the western Himalayas have contributed to a noticeable dip in temperatures, enhancing air quality temporarily.
Temperature Trends and Alerts
Minimum temperatures dropped by more than 6 degrees Celsius in the past 24 hours, settling at 7.6 degrees Celsius on Saturday. The India Meteorological Department (IMD) expects temperatures to fall further on Sunday, January 25, and on Republic Day, January 26. A yellow alert has been issued for January 27, forecasting another spell of rain as a western disturbance approaches the region from the night of January 26.
On Friday, widespread light to moderate rainfall was recorded, with Safdarjung, the base station, logging 19.8mm of rain in the 24 hours ending at 8:30 AM on Saturday. Visibility conditions varied, with Safdarjung reporting 400 metres in moderate fog at 1:30 AM and Palam recording similar visibility at 2 AM.
Forecast: AQI Likely to Worsen
According to the Air Quality Early Warning System by IITM, the relief may be short-lived. The AQI is expected to slip back to the poor category on Sunday. The forecast indicates that air quality is likely to be in the very poor category on January 26 and in the poor category on January 27. For the subsequent six days, the AQI is expected to fluctuate between poor and very poor.
Detailed Weather Predictions
Mahesh Palawat, Vice-President of Skymet, noted that another western disturbance will impact the region on the night of January 26, leading to light rain on January 27. Minimum temperatures may rise briefly but will dip again thereafter. IMD forecasts include:
- A fall in minimum temperatures by 1–2 degrees Celsius over the next two days.
- A rise of 5–6 degrees Celsius during the following two days.
- Another fall of 2–4 degrees Celsius thereafter.
Minimum temperatures are likely to remain below normal for the next two days and above normal on January 27, 29, and 30. Generally cloudy skies with one or two spells of light rain, thunderstorms or lightning, and gusty winds of 30–40 kmph are likely during early morning to forenoon hours.
For Republic Day, improved visibility is expected with stronger winds. The predominant surface wind will be northwesterly at up to 5 kmph in the morning, increasing to 10 kmph in the afternoon, and easing to 8 kmph from the northeast by evening and night. A clear sky and shallow fog are likely on the morning of January 26.
On Saturday, clearer skies pushed the maximum temperature up by over 2 degrees Celsius, with the day's maximum settling at 18.2 degrees Celsius, two notches below normal, compared with 16 degrees Celsius a day earlier.
