<p>New Delhi: Delhiites woke up to a foggy Thursday morning with the minimum temperature settling at 6.6 degrees Celsius, one notch below the season's average, the weather department said.</p>.<p>The Indian Meteorological Department has issued a yellow alert for moderate to dense fog at isolated places in the city for the next two days.</p>.<p>Eighteen trains bound for New Delhi have been running late due to low visibility.</p>.<p>The IGI airport experienced dense fog with visibility ranging between 50 and 100 metres from 12.30 am to 6.30 am. It has now improved and currently the visibility is 300 metres, the IMD said in a tweet.</p>.<p>According to the weather office, very dense fog is when visibility is between 0 and 50 metres, between 51 and 200 metres is dense, between 201 and 500 metres moderate, and between 501 and 1,000 metres shallow.</p>.<p>The maximum temperature is expected to hover around 18 degrees Celsius.</p>.Noida school timings changed to 10 am due to cold weather.<p>According to data by the Central Pollution Control Board (CPCB), the overall Air Quality Index (AQI) at 9 am stood at 368.</p>.<p>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, and 401 and 500 severe.</p>.<p>The relative humidity at 8.30 am was 94 per cent, the IMD bulletin said.</p>
<p>New Delhi: Delhiites woke up to a foggy Thursday morning with the minimum temperature settling at 6.6 degrees Celsius, one notch below the season's average, the weather department said.</p>.<p>The Indian Meteorological Department has issued a yellow alert for moderate to dense fog at isolated places in the city for the next two days.</p>.<p>Eighteen trains bound for New Delhi have been running late due to low visibility.</p>.<p>The IGI airport experienced dense fog with visibility ranging between 50 and 100 metres from 12.30 am to 6.30 am. It has now improved and currently the visibility is 300 metres, the IMD said in a tweet.</p>.<p>According to the weather office, very dense fog is when visibility is between 0 and 50 metres, between 51 and 200 metres is dense, between 201 and 500 metres moderate, and between 501 and 1,000 metres shallow.</p>.<p>The maximum temperature is expected to hover around 18 degrees Celsius.</p>.Noida school timings changed to 10 am due to cold weather.<p>According to data by the Central Pollution Control Board (CPCB), the overall Air Quality Index (AQI) at 9 am stood at 368.</p>.<p>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, and 401 and 500 severe.</p>.<p>The relative humidity at 8.30 am was 94 per cent, the IMD bulletin said.</p>