Fog covering most of England and east Wales descended on Sunday afternoon, and looks set to stick around until at least Monday afternoon.
As a result, drivers have been warned to take extra care on the roads, as poor visibility causes conditions to be hazardous.
The Met Office have issued a yellow weather warning due to the intense fog, which caused many cancellations and delays at airports last night and this morning.
Around 45 flights have been ‘pre-cancelled’ at Heathrow today, while Gatwick is apparently also feeling the effects of the fog.
A spokesperson for Heathrow apologised for the disruption and advised that people planning to fly should check the status of their flight ahead of time.
Meanwhile drivers are being told to avoid unnecessary journeys, and if they do need to drive, use fog lights and take extra time for the journey.