After a warm and bright day across much of Northern Ireland yesterday, many areas will get off to a good start this morning before showers in the west turn increasingly persistent towards the afternoon.
Top temperatures could reach 20C but the rain will spread into eastern areas by early evening.
The best of the early weather will be along the north coast and Fermanagh but Belfast is likely to feel warmer than many other areas. Fermanagh could get temperatures up to 17C while 13C is being forecast for the north west.
Tomorrow will be cooler again with highs of only 13 across many areas.
On the mainland things are looking much better. This weekend is likely to see the hottest day of the year so far with temperatures set to reach higher than in Greece and Italy.
Forecasters said the mercury is expected to rise as high as 24C (75.2F) in much of England today, while in Rome and Athens it is anticipated to be in the low 20s.
Retailers are bracing themselves for a run on BBQ food while thousands of people are likely to flock to beaches and parks to make the most of the sunshine before it becomes more unsettled next week.
A Met Office spokeswoman said yesterday was the warmest day of the year so far for England after the mercury reached 21.9C (71.4F) in Coventry.
The previous top temperature was 21.2C (70.7F), while the highest yet in Britain was 22C (71.6F) in Aviemore, Scotland, on April 28.
London, the South East, East Anglia and the East Midlands will enjoy the highest temperatures today of 23C (73.4F) to 24C (75.2F), while the rest of the UK will also be warm although rain is forecast for north west Scotland and northern parts of Northern Ireland.
The Met Office spokeswoman said: “Most areas are going to see quite a sunny start but it will become cloudy in the South East and South West in the afternoon from about 4pm, although will still be remaining warm.
“The east of England and the South East will be 23C to 24C, with the rest of the country in the mid to high teens or early 20s, particularly in areas that see prolonged sunshine.”
She said Sunday is also expected to be a fine and dry day although parts of Northern Ireland and Scotland are likely to see rain.
Next week will become more unsettled with thundery showers anticipated all over the country although overnight temperatures are also expected to stay warm.