South east London could see its hottest day of the year this weekend as the skies finally clear after weeks of wet and humid weather.

Many parts of the UK could be in for a mini-heat wave – defined as a period of three days or more above a certain threshold.

London and the South East can expect clear skies and highs of 29C on Saturday with the mercury climbing to between 31C and 32C on Sunday.

The sunshine is due to last until so-called “Freedom Day” on Monday, the day when the last of the Covid-19 restrictions are due to be lifted.

The balmy weather, driven by a blast of warm air coming in from the Azores in the North Atlantic, has prompted health officials to issue warnings about the dangers of extreme heat.

The hottest day of the year so far was 29.7C recorded at Teddington in south-west London on June 14.

But we are still a long way away from record temperatures for the time of year – 38.7C was recorded at Cambridge Botanical Gardens on July 25 2019.

Met Office meteorologist Simon Partridge told the PA news agency the weather may take people by surprise “because so far this summer has not been that great”.

“Temperatures have generally been below average for quite a while – it’s the difference in temperature in such a short space of time that is the most noticeable.”

He continued: “But it will affect most of the UK and that is a little bit more unusual – Scotland and Northern Ireland just got their warmest day of the year.

“Northern Ireland might get closer to its highest-ever temperature, which to be fair is only just above 30C.”

But a mini-heat wave is definitely on the cards, the Met Office said, before things turn cooler and thundery from the middle of next week.

For London and the South East to record a heatwave, temperatures must exceed 28C for at least three days, while this drops to 27C in the Midlands and 26C in the South West.