Temperatures dipped as low as minus 4.3C (24F) as icy Arctic air flowed southwards, leaving northern areas with patches of frost and some sleet over high ground in Scotland.
The minimum was recorded at Katesbridge in Co Down, while a low of minus 2.4C (27.7F) was seen at Shap in Cumbria, minus 1.7C (29F) in Sennybridge, Brecknockshire, and minus 1C (30F) at Loch Glascarnoch in the Highlands.
The lowest recorded temperature for the early May bank holiday Monday was minus 5.9C (21.4F) on May 7 2012 at Kinbrace in Sutherland.
Met Office meteorologist Simon Partridge said: “We’re stuck between high pressure to the west of us and low pressure to the east, which is giving us northerly winds - it’s drawing air straight down from the Arctic.”
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Temperatures are expected to peak at 14C (57.2F) or 15C (59F) in the south on Monday afternoon, although northern parts will struggle to see double digits as a band of rain pushes towards the south and east.
“It’s going to be fairly chilly during the day, below average for the time of year, but it’s not going to be too bad and the wind’s going to be light,” Mr Partridge said.
“It will be generally dry, although there is a band of showery rain that’s going to slowly move its way from Scotland southwards through parts of Northern Ireland and northern England then eventually into parts of East Anglia.
“That will make it feel a bit cooler through there, but either side of it will generally be dry and bright with sunny spells.
“It will stay mostly dry in the south, where it will be warmest, so Wales and much of southern England will be fine.”