The Met Office has issued warnings for heavy rain on Wednesday amid fears more cold weather is coming from the east.
Forecasters are predicting a “very cold weekend” with “brisk” winds and the risk of snow showers.
In some places, frosts are forecast to be “severe” and there is a chance the snow could spread to central, eastern and southern parts of the UK.
Some snow showers could also be seen in the West, the Met Office has said.
Yellow warnings have been issued from midday on Wednesday to the same time on Thursday in Northern Ireland because of the likelihood of persistent and occasionally heavy rain and the resulting danger of flooding.
In Cornwall and Devon, the Met Office said journey times may be affected by downpours and a there was also a flood warning until around midnight on Wednesday.
That band of wet weather is expected to move northeastwards across the UK but to weaken.
The sudden drop in temperature at the weekend, with winds from the east, have led to the weather phenomenon being dubbed the “Beast from the East Two” after a similar front brought freezing temperatures and heavy snow to the UK in early March.
Some European forecasters claim snow will hit the South East and East Midlands on Sunday morning.
But Sky weather forecasters say it is too early to say how much is likely to fall.
Weather presenter Nazaneen Ghaffar said: “Very cold conditions are expected to spread westwards across the UK and Ireland later on Friday and through this weekend as easterly winds develop.
“As a result some places may see temperatures fall to only a few degrees above freezing – this most likely across the east of the UK. There will also be a significant wind chill, making it feel colder than the temperatures suggest.
“There has been talk of snow as well, and at this stage Sunday is the most likely day for snow showers. Areas most at risk are central, southern and eastern parts of the UK.
“However it is too early to know how much may accumulate, but current forecasts suggest there is only a low risk of disruption.”
The UK is not the only part of the world to be facing unseasonable weather two weeks after the meteorological start of spring, with the third major storm in two weeks burying some towns in the American North East under up to 2ft feet (60cm) of snow on Tuesday.