Guy Fawkes Night was the coldest of autumn this year, with Britain waking up to frost-covered cars on Monday morning.
A temperature of minus 6C (21.2F) was recorded in Braemar, Aberdeenshire – but that still lagged behind the coldest night of 2017, when minus 10.1C (13.8F) was recorded on January 30 in the same place.
Leaves covered in frost near Ashford, Kent (Gareth Fuller/PA)
It is still some way off the coldest November temperature of last year, when minus 12.1C (10.2F) was registered, again in Braemar.
A largely cloudless night failed to insulate the land and allowed heat to escape, “leading to the widespread frost”, Met Office forecaster Oli Claydon said.
Most of the UK will remain largely bright and chilly for the rest of the week, with highs of around 10C to 12C (50F to 53.6F), he added.
(PA Graphics)
But clouds, wind and rain will be felt across parts of Scotland and the far North West, moving into Northern Ireland and western Wales and western England by Monday night, according to the Met Office forecast.
The band of rain and wind will then move slowly south east, pulling cooler air down with it. Frosty conditions may be seen, particularly in central areas, Mr Claydon added.
Wednesday and Thursday will remain largely dry in the South and South East, but rain is likely to persist in the North West.
For the South on Friday and Saturday, it will be “fairly brisk with showers moving in from the West with periods of sunshine mixed in”, Mr Claydon added.
He said: “The slow-moving cold front is spinning off a low-pressure system. As we move closer to the weekend the system starts to pull cooler air from the North West down, bringing a cooler feel.
“It’s also responsible for the showery set-up we’re likely to see on Friday. Then, there will be fairly widespread blustery cold showers across the UK with periods of brightness mixed in.”
It is too early to predict confidently what conditions will be like from Sunday onwards, the Met Office added.
Seven regions across the UK had “high” or “very high” levels of air pollution on Monday morning, likely owing to bonfires and fireworks, the Department for Environment, Food and Rural Affairs (DEFRA) said.
North Wales and the North West and Merseyside both had “very high” levels.
Meanwhile the Highlands, Central Scotland, East Midlands, the Scottish Borders and Yorkshire and Humberside all recorded “high” levels.
DEFRA said: “These pollution levels were likely elevated due to their proximity to bonfire and firework displays last night.
“These are all expected to gradually clear during the day as winds increase from the west.”
Generally low levels are expected for much of the UK by the end of Monday and for Tuesday as the remnants of Guy Fawkes celebrations clear.