Weather warnings have been issued for thunderstorms and heat alerts extended as the fourth heatwave of the summer continues.
The Met Office has issued a yellow thunderstorm warning covering northern Scotland until 10pm on Thursday.
Flood alerts have also been issued for Scotland.
It comes as heat health alerts were extended into next week for much of England.
The UK Health Security Agency said yellow warnings will now be in place for Yorkshire and Humber, the East and West Midlands, London and the South East, South West and East of England until 6pm on August 18.
The Scottish Environment Protection Agency said heavy thundery showers or rain may affect the region on Thursday, with a risk of significant localised flooding effects from surface water and smaller rivers.
Heavy rain and thunder hit London and Kent on Wednesday afternoon.
But officials have said England is suffering from “nationally significant” water shortfalls.
The national drought group – which includes the Met Office, regulators, government, water companies and other organisations – has met as five areas of the country remain in drought, with six more in prolonged dry weather status.
On Thursday, there will be residual showers and isolated thunderstorms across the South East, gradually clearing, and lightning, hail and heavy rain drifting northwards from Scotland into the Northern Isles.
Paul Gundersen, chief meteorologist at the Met Office, said: “Some areas will continue to experience their fourth heatwave of the summer so far, with Thursday remaining warm or very warm for many, though cooler near coasts.
“Temperatures could still reach 30C in eastern England, though many areas will be a few degrees cooler than earlier in the week.”
Northern England will have patchy rain and cloud on Friday while southern England will enjoy sunshine and temperatures of up to 31C.
The weekend should be dry and sunny for most parts of the UK, climbing to 30C on Saturday and 29C on Sunday in south-west England.
