The UK has recorded its hottest day of the year so far, with temperatures reaching 30.5C in Kent as forecasters warned more extreme heat could follow over the bank holiday weekend.

The temperature in Frittenden also marked the first time since 2012 the UK has reached 30C in May, according to the Met Office.

Forecasters expect the hot weather to continue, with the UK likely to see its hottest May day on record on Monday. Temperatures could reach 33C in southern England and the Midlands.

They are expected to reach 31C on Sunday afternoon in the south and around 26C in the north, the Met Office said.

The current May temperature record is 32.8C, which was logged in Camden Square, north London, in 1922, and in Horsham in West Sussex, Tunbridge Wells in Kent, and Regent’s Park in central London in 1944.

UV levels will also be high across much of the UK over the bank holiday weekend, with a UV index of seven expected in Manchester on Sunday.

Greg Dewhurst, senior meteorologist at the Met Office, told the Press Association: “High pressure will dominate through the whole of the bank holiday weekend.

“Plenty of very warm sunshine across England and Wales each day.

“Scotland and Northern Ireland will see more cloud at times, with a few showers across north-west Scotland.”

The UK Health Security Agency (UKHSA) issued amber heat health alerts for the East Midlands, West Midlands, the east of England, London and the south-east.

The alerts will remain in place until 5pm on Wednesday and replaced less severe yellow alerts, which were previously issued.

The alerts mean there is likely to be “a rise in deaths, particularly among those aged 65 and over or with health conditions” and increased demand on all health and social care services, according to the UKHSA website.

Yellow alerts have been issued for the north-east and north-west of England, Yorkshire and Humber, and the south-west.