Smoggy Conditions Grip Delhi, AQI In 'Very Poor' Category: When Does Fog Turn Into Smog?

New Delhi: The national capital woke up to hazy and smoggy conditions on Wednesday morning, following days of severe air pollution. On Tuesday, the Air Quality Index (AQI) remained close to hazardous levels, reaching 373. This marked the third straight day of deteriorating air quality. The city's pollution woes have worsened with the onset of the season's first fog episode on Tuesday, adding to the dense layer of smog blanketing the area.The temperatures are expected to range between 17 degrees Celsius and 33 degrees Celsius. Winds will vary, blowing from the east-southeast at speeds of 2-4 km/h in the morning, shifting to the northeast at 6-8 km/h by the afternoon, and then easing from the east at 4-6 km/h in the evening. Shallow fog is likely in the morning hours, while mist may settle in during the night. The sky will remain mainly clear throughout the day, on Wednesday.

When Does Fog Turn Into Smog?An IMD official explained that factors like wind speed, humidity, low temperatures, and pollutants all contribute to fog formation near the surface. When the pollution level is already high, this fog becomes "smog," as pollutants combine with moisture to reduce visibility. This occurs because moisture in the air traps pollutants closer to the ground, and low temperatures with calm winds make it difficult for the pollutants to disperse. How Fog is Classified?Fog is classified into different types based on visibility levels: shallow fog is when visibility reduces to up to 500 metres, moderate fog up to 200 metres, dense fog up to 50 metres, and very dense fog when visibility is less than 50 metres. Region Wise AQI Data (As of 6 am on Wednesday) 1. AlipurAQI: Very Poor (372) 2. Ashok ViharAQI: Very Poor (398) 3. Aya NagarAQI: Very Poor (333) 4. BawanaAQI: Severe (414) 5. DTUAQI: Very Poor (360) 6. Lodhi RoadAQI: Poor (265) 7. RK PuramAQI: Very Poor (373) 8. ShadipurAQI: Very Poor (370)

An AQI between zero and 50 is considered good', 51 and 100 satisfactory', 101 and 200 moderate', 201 and 300 poor', 301 and 400 very poor', 401 and 450 severe' and above 450 severe plus'.