Station-wise data showed that Nehru Nagar recorded the worst air quality at 360 in the `very poor` category. While 21 stations logged `very poor` air quality, 14 stations were in the `poor` category and two stations recorded `moderate` air quality

The city recorded poor air quality on Tuesday. According to the CPCB classification, an AQI between 0 and 50 is considered `good`, 51 to 100 `satisfactory`, 101 to 200 `moderate`, 201 to 300 `poor`, 301 to 400 `very poor` and 401 to 500 `severe`

The India Meteorological Department (IMD) has issued a yellow alert for dense fog during morning and forenoon. It has also forecasted a cold day

A yellow alert is an early warning signal showing that severe weather conditions are to be expected and may affect day-to-day activities

On Tuesday, Delhi recorded its first cold day this year and the weather office forecasted that the conditions may persist on Wednesday. Cold day conditions are when the maximum temperatures fall about 4.5 to 6.5 notches below normal