Scotland has enjoyed its warmest September day in 115 years – but forecasters have warned thunderstorms will bring the mini heatwave to an end.
The Met Office confirmed a high of 28.6C (83.5F) in Charterhall in the Borders on Wednesday – Scotland's warmest September day since 1906 when Gordon Castle in Moray reached 32.2C (90F).
It comes after Wales had its warmest September night on record – Aberporth saw a 24-hour minimum temperature of 20.5C (69F), breaking the previous record of 18.9C (66F) set in 1949 in Rhyl.
Cooler temperatures are expected to return to much of the UK in the coming days with unsettled conditions sweeping across large parts of the country.
A yellow weather warning for thunderstorms and heavy rain on Thursday is in place for Scotland, Wales, Northern Ireland and much of England.
Downpours and flooding will be expected between 10am and 8pm – with the Met Office warning the conditions could lead to property damage and disrupt travel.
The only areas of England not covered by the warning is East Anglia and southern parts.
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"Almost everywhere could see some storms on Thursday," the Met Office spokesman added.
The Scottish Environment Protection Agency has issued flood warnings for many regions.
Alerts are in place for Aberdeenshire and Aberdeen City, Argyll and Bute, Ayrshire and Arran, Caithness and Sutherland, Central, Dumfries and Galloway, Dundee and Angus, Easter Ross and Great Glen, Edinburgh and Lothians, Fife, Findhorn Nairn Moray and Speyside, Scottish Borders, Skye and Lochaber, Tayside, West Central Scotland, Wester Ross and Western Isles.
Meanwhile, Devon and Somerset Fire and Rescue Service was called to Mount Street Primary School in Plymouth shortly before 10am after the building was struck by lightning.
Pupils were left with wet clothing after being evacuated from the school in heavy rain. No one was injured in the incident.
Thunderstorms also caused flash flooding in the seaside town of Salcombe, where police said dozens of businesses had been affected.
The UK has been basking in the late summer heat this week, with the highest temperature on Tuesday reaching 30.7C (87.3F) at Gogerddan, in Dyfed, Wales, according to the Met Office.
Highs of 30.4C (86.7F) were recorded in west London and 30.3C (86.5F) at Pershore in Worcestershire.