The Met Office has issued a yellow alert for North Herts and South Cambridgeshire – with heavy rainfall, thunderstorms, and possibly hail forecast for tomorrow afternoon.

The rain is expected between 1pm and 11pm on Friday, June 2, most likely at 2pm, when there is a 40 per cent chance of rain.

The Met Office has said very warm, humid air coming up from France is creating the threat of thunderstorms, which could produce between 25 and 30mm of rain in an hour.

The alert covers most of Hertfordshire – including Royston – with South Cambridgeshire also set to be affected. The warning covers Bedfordshire, Essex and East Anglia too.

There is the risk the rainfall could create some surface water on the roads, which won’t be helped by frequent lightning and possible hail.