Continuous snowfall since Tuesday night has blocked access to areas such as Lachung, Yumthang, Lachen and Uttarey in West Sikkim district, they said as reported by PTI.
The road to Tsomgo Lake and Nathula has also been closed due to heavy snowfall, the report said.
The state capital Gangtok reported the season's lowest minimum temperature of 3.1 degrees Celsius, the Met department said.
The temperature will drop further in the next two days, it said.