Much of the UK woke up to a cloudy, grey start to Sunday, with some rain and drizzle in parts of northern Ireland, northern England and Scotland.
The rain is expected to clear during the day, while in the south of the UK, most areas will be dry with sunny spells developing later.
Temperatures on Sunday will become increasingly warm as the clouds break up in the north and winds are lighter than they have been over the past couple of days, said Met Office meteorologist Alex Burkill.
“Tonight will be largely clear, with some patches of mist and fog, but the clear conditions mean it will be a bit chillier,” he said.
“In some rural spots, temperatures could be as low as 3C to 4C, so there may be a touch of grass frost but to be honest, most people will still be asleep by the time it clears on Monday morning.”
Bank holiday Monday is expected to be largely sunny for the bulk of the UK, with some cloud and rain in the northwest pushing away as the day goes on.
Tomorrow will reach highs of 25C, possibly 26C, which is “quite a few degrees above average” for May, said Mr Burkill. Average temperatures for May in London usually hover between 18C to 19C.
The rest of the week will see similar temperatures, although conditions may be cloudier in northern parts of England and Wales with some outbreaks of rain. Most of the UK can expect to bask in warm, sunny spells.
“Although it’s warmer than average, we would not consider this coming warm spell to be a heatwave as we are coming to the end of May,” said Mr Burkill.
“The May bank holiday is not expected to break any temperature records – the warmest May bank holiday was in 2018, with a high of 27.6C, and we’re not expecting that tomorrow.”
Britons are reminded to avoid crowding at beaches or parks even as the mercury rises, and to practice social distancing if they do venture into outdoor areas to enjoy the weather as the coronavirus lockdown continues.