Temperatures in London soared to 23C on Thursday afternoon ahead of a “mini heatwave” this weekend.
Forecasters said that the UK could see the hottest day of the year so far on Sunday, with temperatures predicted to peak at 26C in south east England.
In London, the mercury will peak at 25C on Sunday afternoon.
Dry and sunny conditions are forecast for the capital throughout the weekend.
Andrea Bishop, spokesperson at the Met Office, told the Mirror: “High pressure dominates at the moment. The temperatures will be slightly above average for the time of year and Saturday is looking like the warmest day this week, when temperatures could peak at 26C.”
She warned that hayfever sufferers should also take precautions with high levels of pollen forecast for the weekend.
“There are instances of high pollen levels and UV levels over the next few days, including Saturday, so we are encouraging people to be aware,” she added.
The Met Office said the weather would change from Monday and return to “unsettled and showery” conditions, with rainfall “above average” in many parts of the country.
Temperatures will fall to an average of between 17C-18C in London from Tuesday.
Deputy Chief Meteorologist Tony Wisson said: “Many places will start fine and warm on Sunday, though it is likely to become cloudier from the west or southwest during the day. This will be accompanied by scattered showers, which could be heavy with thunder.
“On Monday we're likely to see more widespread and longer-lived spells of rain, some of which will be heavy and thundery. This will also lead to a much cooler feel to the day.”
Londoners could face difficulty leaving the capital as a stretch of the M25 in Surrey will be closed to allow concrete beams for a gyratory bridge and a gantry to be lifted into place.
A ban on overtime by the Aslef union will remain in place until Saturday, which may alter train timetables.
