The falls are expected to stop by the morning, but the accumulations could still cause disruption for commuters.
More light flurries are predicted for Monday and Tuesday, after which the week is expected to turn milder.
Thousands of passengers have been stranded in America after flights to Britain were grounded when a massive snowstorm hit the US east coast.
It dumped more than 3ft of snow from Massachusetts to New Jersey, while hurricane-force winds battered the eastern states and up into Canada, killing at least eight people.
Heathrow Airport said 10 inbound flights - all from New York and Boston - were cancelled, as was one outbound flight, to Washington. British Airways, Virgin Atlantic, Delta Air Lines, United Airlines and Air Canada were all forced to cancel flights on Sunday, Heathrow said. Passengers were advised to check if their flights are affected with their airlines.