Schools have been closed, flights delayed and commuters are facing hazardous road conditions after heavy snowfall last night.
The north of England has been blanketed, with as much as 10cm of snow reported on high ground.
Leeds Bradford Airport was forced to close as crews work to clear the runway, which could cause delays to flights later today.
A spokesman said: "We have had 5cm of snow, it started at 1am. The snow-clearing teams are out on the runway making sure we can reopen as soon as possible."
Eight schools in Leeds, 20 in East Lancashire and 28 in West Yorkshire are closed.
The Met Office has warned motorists to allow extra time for journeys because of icy conditions on the roads.
Weather warnings were issued for Northern Ireland, north Wales, northern and western England and Scotland as a frontal system came in from the Atlantic.
By the early hours of Friday just over an inch had fallen across high ground in northern England.
Similar snowfall was recorded at Leek in Staffordshire and Shap in Cumbria, and several A roads were closed over the high Pennines in south Yorkshire.
Strong, north-easterly winds and wintry showers in many places will ensure temperatures remain below normal at least until the middle of next week.