The lifting of lockdown restrictions to allow people in England to use pub beer gardens and dine in the outdoor areas of restaurants is being met by snowfall, as a spring cold snap hits.
The inclement weather will come as a blow to thousands of businesses that were hoping to welcome back customers on Monday after months of restrictions.
Met Office forecasters said southern England and much of Wales could expect outbreaks of rain, sleet and some snow, although this was predicted to clear through the morning, leaving sunny intervals and scattered showers.
Elsewhere in the UK, people were told to expect sunny periods and isolated wintry showers. The Met Office said temperatures were not expected to rise beyond single figures celsius.
Non-essential shops, hairdressers, indoor gyms, swimming pools, nail salons and zoos in England are also opening for the first time this year.
A number of pubs with 24-hour licences opened as soon as they were allowed. The Kentish Belle in south-east London opened at one minute past midnight on Monday until 3am. In Newcastle, the Switch bar and the Bank did the same, despite temperatures dropping below freezing.
Boris Johnson said people should enjoy the new freedoms but remain wary of the risks. In a message hailing the latest stage of lockdown lifting, the prime minister said: “Today is a major step forward in our roadmap to freedom as venues such as shops, hairdressers, nail salons, outdoor attractions, and pubs and restaurants open once again,” he said.
“I’m sure it will be a huge relief for those business owners who have been closed for so long, and for everyone else it’s a chance to get back to doing some of the things we love and have missed.”
Johnson also stressed the need for “fresh air” as a key Covid-19 prevention measure, alongside the familiar messages of handwashing, social distancing and mask-wearing.
“I urge everyone to continue to behave responsibly and remember ‘hands, face, space and fresh air’ to suppress Covid as we push on with our vaccination programme,” he said.
After a cold April weekend, during which many areas experienced a light dusting of snow, temperatures of between 0C (32F) and -2C were expected in the early hours of the morning across the UK. Heavy rain and hill snow was also forecast for Northern Ireland and west Wales on Monday morning.
The Met Office said rain showers would move south-eastwards throughout the day, hitting the Midlands by mid-morning and reaching the south coast by the afternoon and into the evening.
No flood warnings were in place on Sunday night, but the Environment Agency issued six lower-level alerts for scattered locations in south-west England where flooding was possible.
Meanwhile, people in northern England and Scotland can expect to see a cold but sunny and dry start to the week.
Average midday temperatures range from 6C in the Scottish isles to 12C in Cornwall, with 10C forecast for London and 7C in Manchester.
A chilly night was expected to follow on Tuesday, with freezing temperatures forecast across the UK. The rest of the week was likely to be cold but dry, the Met Office said.