Forecasters warn thunderstorms are set to hit parts of the UK before temperatures reach 30C over the weekend.
Wednesday is due to be “humid and very warm” in the south of England, with a “threat of heavy, possibly thundery showers” later in the day, the Met Office said.
Thunderstorms with “lightning, hail, and heavy rain” may lash the south east of England overnight before clearing on Thursday, forecaster Paul Gundersen said.
“Elsewhere through Thursday, rain will move eastwards across the UK, clearing to showers, with some sunny spells breaking through at times. Friday will start dry in the east, with rain moving in from the west, becoming showery later.”
Mr Gundersen said that many parts of the country will stay dry on Saturday, with a patch of rain moving southeast and easing.
Sunday is due to see “variable cloud and showers” in the north, with “patchy rain and drizzle” in the west, but otherwise stay dry with sunny spells, he added.
Parts of the south are set to hit highs of 30C over the weekend, which would be hotter than Rio de Janeiro in Brazil, according to forecasts.
Oli Claydon, spokesman for the Met Office, said: “It’s a little bit uncertain, potentially we could remain in the 30s in the far South East of England, and it’s quite a long way ahead, there is potential there and if it did reach into the 30s in the South East we could be looking at a short-lived localised heatwave.”
So, Glastonbury-goers can expect a mixed bag of sunshine and rain this week.
More than 200,000 people are expected to descend on the fields of Pilton, with ticket-holders advised to prepare for mainly warm weather, but to also bring waterproofs to the five-day event.
It comes after a provisional high of 33.2C was recorded by the weather service on June 21 in Charlwood, Surrey, making it the warmest day so far of 2025.
Last week, the Met Office said “many places” in England and “one or two areas” in Wales, including Cardiff, entered a heatwave on June 20.
So far, June’s average daytime temperatures have been 19.2C, slightly above the average of 17.68C, according to the Met Office.
