Temperatures could soar over 30C in some parts of the UK over the weekend and early part of next week.
Sunday and Monday are expected to be the hottest days, with temperatures of up to the “mid-30s” expected in the south east of England, according to BBC Weather.
Other parts of southern and eastern England, as well as the Midlands and south Wales, may also experience rising temperatures
The hot spell is being linked to Storm Debby, which has caused severe flooding and heavy rain in the US.
The storm itself will not reach the UK, but a plume of hot and humid air across Spain and France will move northwards and affect parts of England and Wales, BBC Weather said.
A buckle in the jet stream attributed to the energy input from Storm Debby is thought to be behind the warmer weather.
The jet stream is a fast-flowing current of air that travels around the planet. It occurs when warmer air from the south meets cooler air from the north.
The blast of heat may be short lived, with heavy and thundery showers likely to develop as cooler air moves in on Tuesday.
“Although still a little uncertain at present, temperatures are likely to get into the low 30s Celsius across the south-east of England, and possibly even a little hotter,” BBC Weather presenter Stav Danaos said.
“There is a chance of something around the mid-30s in the hottest spots.”
By next week, forecasters suggest temperatures will return to closer to normal across the whole of the UK.
Before Sunday, conditions will remain fairly changeable, with rain expected in western parts of the country on Thursday, before sunny spells for certain areas on Friday and humid weather on Saturday.
Conditions could be windier than usual in some western and north western areas.
Many parts of the world are currently experiencing above-average temperatures, with meteorologists saying this is largely a result of global warming.