<p>New Delhi: The layer of early-morning fog over the Indo-Gangetic plains in north India thinned in some parts on Wednesday, officials said.</p>.<p>Satellite imagery showed a reduction in fog over Bihar, eastern Uttar Pradesh, northern Madhya Pradesh and Delhi.</p>.<p>However, dense fog continues to prevail over parts of Punjab, Haryana, western Uttar Pradesh and Rajasthan.</p>.<p>A spokesperson for the Indian Railways said that 20 trains arriving in Delhi were delayed by up to five hours due to foggy weather.</p>.<p>At 5:30 am, visibility levels stood at 25 metres in Patiala, Ambala and Bareilly, 50 metres in Hisar, Churu and Bahraich and 200 metres in Lucknow and Purnea.</p>.<p>At the Palam Observatory near the Indira Gandhi International (IGI) Airport in Delhi, visibility was limited to only 200 m.</p>.<p>Early-morning foggy weather in north and northeast India has heavily impacted road, rail and air traffic over the last fortnight.</p>.<p>On Monday, five flights were diverted and more than 100 delayed at the Delhi airport.</p>.<p>Civil Aviation Minister Jyotiraditya Scindia said on Monday that all stakeholders are working round-the-clock to minimise fog-related disruptions.</p>.53 flights cancelled as Delhi airport grapples with fog, operational issues.<p>The Delhi airport was asked to expedite the operationalisation of the CAT III-enabled fourth runway in addition to the existing CAT III-enabled runways.</p>.<p>Generally, CAT III compliance refers to flight operations in low-visibility conditions.</p>.<p>As the blinding fog lowered visibility levels at several places on Tuesday night, the India Meteorological Department (IMD) advised people to avoid unnecessary travel and take precautions while driving.</p>.<p>The IMD said dense to very dense fog conditions are likely to prevail over north India for the next five days.</p>.<p>It said cold-day to severe-cold-day conditions would persist over the northern plains for two more days.</p>.<p>"Cold wave to severe cold wave conditions are likely to continue over northwest India for five days," it said.</p>.<p>In the plains, the MeT office declares a cold wave if the minimum temperature dips to 4 degrees Celsius or when the minimum temperature is 10 degrees or below and is four-and-a-half notches below the normal.</p>.<p>A severe cold wave is when the minimum temperature dips to 2 degrees Celsius or the departure from the normal is by more than 6.4 degrees.</p>.<p>A cold day is when the minimum temperature is less than or equal to 10 degrees Celsius below the normal and the maximum temperature is at least 4.5 degrees below normal.</p>.<p>A severe cold day is when the maximum is 6.5 degrees Celsius or more below normal.</p>
<p>New Delhi: The layer of early-morning fog over the Indo-Gangetic plains in north India thinned in some parts on Wednesday, officials said.</p>.<p>Satellite imagery showed a reduction in fog over Bihar, eastern Uttar Pradesh, northern Madhya Pradesh and Delhi.</p>.<p>However, dense fog continues to prevail over parts of Punjab, Haryana, western Uttar Pradesh and Rajasthan.</p>.<p>A spokesperson for the Indian Railways said that 20 trains arriving in Delhi were delayed by up to five hours due to foggy weather.</p>.<p>At 5:30 am, visibility levels stood at 25 metres in Patiala, Ambala and Bareilly, 50 metres in Hisar, Churu and Bahraich and 200 metres in Lucknow and Purnea.</p>.<p>At the Palam Observatory near the Indira Gandhi International (IGI) Airport in Delhi, visibility was limited to only 200 m.</p>.<p>Early-morning foggy weather in north and northeast India has heavily impacted road, rail and air traffic over the last fortnight.</p>.<p>On Monday, five flights were diverted and more than 100 delayed at the Delhi airport.</p>.<p>Civil Aviation Minister Jyotiraditya Scindia said on Monday that all stakeholders are working round-the-clock to minimise fog-related disruptions.</p>.53 flights cancelled as Delhi airport grapples with fog, operational issues.<p>The Delhi airport was asked to expedite the operationalisation of the CAT III-enabled fourth runway in addition to the existing CAT III-enabled runways.</p>.<p>Generally, CAT III compliance refers to flight operations in low-visibility conditions.</p>.<p>As the blinding fog lowered visibility levels at several places on Tuesday night, the India Meteorological Department (IMD) advised people to avoid unnecessary travel and take precautions while driving.</p>.<p>The IMD said dense to very dense fog conditions are likely to prevail over north India for the next five days.</p>.<p>It said cold-day to severe-cold-day conditions would persist over the northern plains for two more days.</p>.<p>"Cold wave to severe cold wave conditions are likely to continue over northwest India for five days," it said.</p>.<p>In the plains, the MeT office declares a cold wave if the minimum temperature dips to 4 degrees Celsius or when the minimum temperature is 10 degrees or below and is four-and-a-half notches below the normal.</p>.<p>A severe cold wave is when the minimum temperature dips to 2 degrees Celsius or the departure from the normal is by more than 6.4 degrees.</p>.<p>A cold day is when the minimum temperature is less than or equal to 10 degrees Celsius below the normal and the maximum temperature is at least 4.5 degrees below normal.</p>.<p>A severe cold day is when the maximum is 6.5 degrees Celsius or more below normal.</p>