Meteorologist Aidan McGivern said: “With the clearest skies further north, that’s where the coldest air will be by dawn on Thursday.
“Minus two in some sheltered Scottish glens, close to freezing fairly widely in the northern half of Britain and some fog patches too in southwest Scotland, Northern Ireland and northwest England.”
These fog patches should lift soon though and countrywide there should be sunny spells developing.
There will be patchy cloud hovering over the southern counties of England near the Channel, but for most people it’s a “sunny day” and a “fine afternoon”.
Temperatures will max out at about 15 or 16 degrees.
Throughout the day, England and Wales’s weather will be largely problem-free, with “plenty of sunshine”.
However, there is also likely to be fog on Thursday night coming into Friday morning – in the Vale of York and across central parts of England into the south.
This weather is caused by high pressure over the country during today and tomorrow.
Mr McGivern said: “High pressure well and truly in charge through Thursday, giving all of us a fine day.
“But as a weather front starts to approach late on Thursday from the northwest we’ll see the breeze pick up.”
Layers of cloud will start moving across Scotland, Northern Ireland and northern England, which means it will not be “quite as chilly” in the north on Thursday night.
There will still be “one or two” pockets of frost and fog.
First thing Friday morning will be chilly, but it is looking to warm up to similar temperatures, 15 or 16 degrees.
Some forecasters have warned this summer could see a repeat of last year’s bitter winter.
Chief Meteorologist John Hammond said: “The most recent computer output has shifted, and I’m not surprised.
“It’s looking more likely now that ‘atmospheric blocking’ may periodically stop the westerlies in their tracks.
“This will allow weeks of much colder continental air to hold sway, bringing a great threat of snowfall.”
He added: “It may well be that the UK repeatedly finds itself in the middle of this ‘battleground’.”