Britain's elusive "barbecue summer" will make a brief appearance this week, with parts of the country expected to bask in sultry temperatures.
By midweek, southern and eastern parts of the country will be enjoying sunshine and blue skies, with the mercury predicted to hit 29C on Wednesday.
But the fine weather will be fleeting as a cool front moves in from the West.
Helen Rossington, forecaster at the MeteoGroup, the weather division of the Press Association, said: "There are no signs of high pressure forming for a long time over the UK."
Back in April, the Met Office issued a seasonal forecast with a claim that the UK was "odds-on for a barbecue summer".
However, a hot spell at the end of June and at the beginning of last month ended in a wash-out with higher-than-average rainfall in July.
Ms Rossington said: "The warmest weather this week will be in London and the South East. There will be more cloud around in western England, Scotland and Northern Ireland with a risk of heavy showers and thunder. It will feel much cooler there - around 19 or 20C.
"A cool front moving in from the West on Wednesday night and Thursday morning will bring fresher air and temperatures in the low 20s."
