Delhi fog LIVE updates: Traffic police tweets list of dos and don'ts for drivers, advises motorists to be cautious

Fog at Crossings Republic in Ghaziabad. Image courtesy: Aninda Ray/Firstpost[/caption]As many as 27 trains running are running late, and several flights are delayed. Images shared on social media show vehicles on Delhi roads barely visible through the dense fog. Several airlines have advised flyers to check their flight status beforehand. The Delhi Traffic Police has issued an advisory on dos and don'ts.The India Meteorological Department has also warned of dense to very dense fog in Delhi-NCR due to the cold wave.With a cold wave gripping the region, a large number of homeless have been taking refuge at night shelters in various parts of Delhi to shield themselves from chilly winds. The maximum temperature in Delhi on Sunday was 19.9°C, two notches below the season's average. The minimum temperature was 9.4°C, a notch above the season's average. On Monday, the maximum and minimum temperatures are likely to be around 21 and 11°C.Air Quality Index in the range of 51 to 100 is considered satisfactory; 101-200 is moderate; 201-300 falls under the category of poor; 300-400 is considered 'very poor'; and 401-500 falls under the 'hazardous' category.