THE Met Office has issued a yellow weather warning for rain - with possible hail and lightning - across the southern half of England and for Wales until tomorrow evening.

Slow-moving heavy downpours are forecast to spread over the southern half of the UK, hitting festival-goers at Glastonbury, where steady rain fell this morning, and stopping play away from Centre Court at Wimbledon.

The Met Office warned that up to 40mm (1.6 inches) of rain could fall in two or three hours, causing localised flooding and disruption to transport and outdoor events in some areas, while hail and lightning would be additional hazards.

Following a lull in activity overnight, further slow-moving thundery downpours are likely to develop during Saturday, the Met Office said, with the greatest risk increasingly towards the south of the warning region later in the day.

This month is expected to be one of the warmest Junes on record.

The Met Office said that early figures put this June as joint sixth warmest across the UK in the records stretching back to 1910, with an average temperature of 14.4C (57.9F) up to June 25.

It is likely to be in the top 10 warmest Junes once the final figures are in.

The warmest June on record came in the scorching summer of 1976, when the average temperature for the month was 15C (59F).

"This continues a run of seven months where the UK mean temperature was warmer than average, with all the months from December through to April each being at least 1C warmer than the long-term average," the Met Office said on its blog.

Scotland has experienced its second warmest June on record so far, with an average temperature of 13.2C (55.8F), beaten only by 1940 when temperatures averaged 13.5C (56.3F). In England, Wales and Northern Ireland, June is currently the ninth warmest on record.

The Met Office figures also show sunshine totals have been near normal, with June seeing the sunniest weather over south-west England and Wales but duller conditions in Scotland.

And rainfall totals have been below normal overall.