Britons hoping to enjoy their first pint at a beer garden for more than three months will need to wrap up warm, as snow and chilly temperatures are forecast across much of England.
The Met Office has said Monday morning will be bright in the north, while areas in the southern half of the UK are likely to be hit by a rain front moving eastwards throughout the day.
Along with beer gardens and outdoor dining areas, non-essential shops, hairdressers, indoor gyms, swimming pools, nail salons and zoos in England will also be opening for the first time this year.
Following a cold April weekend where many areas experienced a light dusting of snow, temperatures of between 0C (32F) and -2C (28.4F) are expected in the early hours of the morning across Britain.
Heavy rain and hill snow is also forecast for Northern Ireland and west Wales in the morning.
The Met Office has said rain showers will 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 has issued six lower-level alerts for scattered locations in south-west England where flooding is 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 (42.8F) in the Scottish isles to 12C (53.6F) in Cornwall, with 10C (50F) forecast for London and 7C (44.6F) in Manchester.
A chilly night is due to follow on Tuesday, with freezing temperatures forecast across the UK.
The rest of the week is set to be cold but dry, the Met Office has said.