Adrian Lynch has not been seen since around 2 am on Saturday when he was spotted in the area of Bon Air Riding Stables on La Grande Route de Saint Laurent.
He had been dropped off by a taxi in the area of Six Roads, St Lawrence, just after midnight.
His wallet and phone were found close by.
Home and property owners in St Lawrence, St John and St Mary are being urged to check their outbuildings, sheds, land and gardens and to contact Police Headquarters with any information.
Searches took place overnight and are continuing today, involving officers from the States of Jersey Police, as well as members of Jersey Search and Rescue, the Honorary Police and the Fire and Ambulance services.
The Channel Islands Air Search plane is also taking part in the search.
Officers are with Mr Lynch’s family.
Chief Inspector Lee Turner said: ‘We’d like to stress that Adrian now has been missing for two nights.
‘With the cold weather and windy weather we have been having we are concerned for his safety.
‘He’s dressed only in a light suit and he is not dressed for the adverse weather we are currently experiencing.’
Police say that the 20-year-old had consumed alcohol before his disappearance, but was described as being ‘talkative’ and ‘steady on his feet’.
Members of the public have been offering to help with the search for Mr Lynch, but Police said that this was not required at this time.
Mr Lynch is described as slim to proportionate build, with short straight black hair and of Asian appearance.
When he was last seen he was wearing a light blue suit and a white shirt.
