LUCKNOW, Dec. 24 -- The meteorological department has issued an orange alert for dense to very dense fog in several districts of western and eastern Uttar Pradesh on Wednesday and Thursday. The forecast for Lucknow is moderate fog during morning hours and clear skies later. On Wednesday, the maximum and minimum temperatures may be around 21 and 12 degrees Celsius respectively. Across the state, the weather is most likely to remain dry. "Due to the persistent layer of fog in the northern Terai districts of the state and the adjoining districts of Purvanchal, cold day conditions prevailed during the day in Kanpur, Gorakhpur, and Sultanpur, while severe cold day conditions continued in Bahraich and Basti on Tuesday," said Atul Kumar Singh, a senior scientist at the Lucknow met office. In Lucknow, mercury hovered between 20.2 and 10.4 degrees Celsius. Ghaziabad, Bareilly, Saharanpur and Agra experienced zero visibility as very dense fog gripped most parts of West UP. Visibility stood at 50 metres in Lucknow and Ayodhya, 100 metres in Meerut and Etawah, and 400 metres in Moradabad and Jhansi. Five districts that recorded the lowest minimum temperatures are Etawah (6.8 degrees), Churk (7), Barabanki (7.4), Kanpur City (7.7) and Muzaffarnagar (8.1). Meanwhile, Bahraich recorded the lowest day temperature at 13.4 degrees, which is nearly 8 degrees below normal....