Bosses said they would reach a decision on Sunday about whether or not to take pre-emptive action.
Heathrow PR, Marianna Panizza, said: “Monday has a snow risk and we’re preparing in accordance with our snow plan, which includes cancelling flights in advance to reduce disruption when snow arrives.”
Johnson was not impressed and used the announcement to champion his view that London needs a new airport.
He said: “This shows time and again the difficulty at Heathrow. Every time there is a slight problem, Heathrow cannot cope.
“The answer is not a third runway, but another hub airport for London and the South-East," reports the Telegraph.
It said: "This weather could increase the health risks to vulnerable patients and disrupt the delivery of services."
Nick Prebble, a forecaster for MeteoGroup, the weather division of the Press Association, said: "A lot of people will be waking up to snow in Scotland this morning and there will be a light dusting in north-east England and Yorkshire.
"The snow will spread south-eastwards throughout the course of the day reaching Manchester, and overnight much of England will have snow flurries.
"But it will be throughout Monday when the heaviest snow falls, affecting central and east England and northern Wales.
Spokesman Simon Williams said: “We urge motorists to avoid all non-essential journeys in heavy snow.
“Even half an inch of snow can bring roads to a standstill and leave drivers stranded.”