With overnight rains in many parts of the state, the Met Office said the winter chill had set in.
The night temperature in Lucknow were recorded at 1.7 degrees Celsius, making it the coldest night in many years.
Undeterred by the inclement weather, revellers said they would party on the year end.
"It is the last day of the new year and we will let our hairs down, no matter what the weather," says Anshuman, an MBA student who has booked an eatery to enjoy with his friends.
Many eateries, food joints and clubs owners, however, are keeping their fingers crossed as they fear that weather may play spoilsport in the new year bash.
According to the weather office, Muzaffarnagar was the coldest Monday with night temperatures plummeting to 0.3 degrees.
Mercury fell to 1.2 degrees in Kanpur, forcing people to stay indoors. The fall of temperatures in the past two days has been steep and the night temperatures have fallen by more than 3.3 degrees.
Regional Met director J.P. Gupta said, icy winds coming from the hills were going to further aggravate the winter chill in days to come.
The Met Department predicted slight rain in many parts of the state till Thursday.
Foggy conditions on outskirts of many areas also affected train and vehicular traffic with the Northern Railway cancelling six trains and more than 16 trains running much behind schedule.
Trains that were running late by several hours, included Agra Intercity, Farakka Express and Licchvi Express.
--IANS (Posted on 31-12-2013)