Rain and cloud to sweep across the country to end warmest May since records began

Rain: Thunderstorms are expected to stir up unsettled weather

The South is set to bear the brunt of the rain today, with a high chance of thunderstorms across many areas, and the thermometer plunging to the low 20s.

And by the end of the week rain is expect to sweep across the whole country with temperatures dropping to the mid-teens.

There is some good news for those desperate for summer to continue as sunshine is expected to puncture through the unsettled weather.

May has so far been the warmest for the period since records – the world's oldest weather log – began in 1772.

For Scotland it has been the warmest first period of May since 1990, while for England, Wales and Northern Ireland it has been the warmest since 1995.

It peaked at an unseasonable 79F in Lee-on-the-Solent, Hampshire at the start of the week. The sunshine has seen crowds flock to beaches in Brighton, Bournemouth and many resorts across the country to soak up the rays.

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Meanwhile, firms reported large numbers of missing workers who preferred to stay out in the sun than be cramped up in the office.

The Met Office's John Hammond said: "Over the next few days it will get less warm – although it will still be above average for May."