Temperatures are forecast to build this week, with heatwave thresholds likely to be met for much of the UK, particularly England and Wales, according to the Met Office.
The heat will build through the week, likely peaking on Friday and Saturday thanks to the influence of high pressure.
Temperatures are likely to rise into the low-to-mid 30s Celsius for central and southern areas of the UK. However, temperatures are not expected to be as extreme as those experienced in July when new national records were set.
Away from the highest temperatures expected in central and southern areas, much of England and Wales, as well as the southeast of Scotland, could still see temperatures widely into the high 20s Celsius, with a chance of a few spots seeing temperatures into the low 30s.
Scotland and Northern Ireland will also see temperatures into the high 20s and could reach official heatwave criteria by Friday.
Met Office Deputy Chief Meteorologist Tony Wardle said:
“Heatwave criteria look likely to be met for large areas of the UK later this week, with the hottest areas expected in central and southern England and Wales on Friday and Saturday.
“Temperatures could peak at 35C, or even an isolated 36C on Saturday.
“Elsewhere will see temperatures widely into the high 20s and low 30s Celsius later this week as temperatures build day-on-day through the week due to an area of high pressure extending over much of the UK.
“Coupled with the high daytime temperatures will be continued warm nights, with the mercury expected to drop to only around low 20s Celsius for some areas in the south.”