According to reports parts of the country could see the temperature drop to minus 15C, with Scotland suffering most.
Last night parts of Scotland experienced lows of minus 7.1C and the Met Office is urging people to prepare for the worst.
Forecaster Krista Mitchell told the Daily Mail: "There are some very cold conditions forecast for tonight and the rest of the week. This is because of cold air coming from the Arctic.
"We could see the coldest night in three years tonight. Motorists should check conditions before travelling because of the icy conditions."
Along with the severe cold, some parts are expected to experience snow showers.
The weather has already caused accidents up and down the country today, and conditions are only expected to get worse.
While the rest of the country won't see such extreme temperatures, London and the south coast will drop to minus 1C.
Due to the health complications the freezing weather can cause, homelessness charity St Mungo's have urged anyone who sees someone sleeping rough to contact 0300 500 0914 to help find them somewhere to stay.