After a cool and wet start to June, temperatures are set to rise again by the end of this week – but there is uncertainty about just how warm it will get, according to BBC Weather’s lead presenter Simon King.
With high pressure building, it will turn drier and sunnier for most areas of the UK. Parts of England and Wales are likely to see highs in the mid-twenties Celsius, with Scotland and Northern Ireland reaching the low-twenties. Some computer models suggest it could get a little warmer than that, but it is too early to say whether it will be warm enough for long enough for an official heatwave to be declared.
“Temperatures could reach 25-27C by this weekend but models disagree on whether it will be a heatwave.”
Before the weather settles down, more heavy rain and thunderstorms are in the forecast. On Wednesday heavy showers are expected across the UK with a high chance of some of these being thundery in eastern Scotland and eastern England. It will feel cool for the time of year again with temperatures around 3 to 6C below average.
Lower temperatures will persist into Thursday as a large area of rain moves in from the west across many parts of the UK. While it will get drier, brighter and slightly warmer on Friday, it is the weekend when high pressure gradually builds in from the south, turning things drier. It could turn significantly warmer too – depending on what shape that area of high pressure takes.
With just a few days to go until the weekend, computer weather models disagree about how warm it might get. Some allow for high pressure to move right across the UK, allowing southerly breezes to develop. That could lift temperatures to 25-27C (77 to 80F) in parts of England and Wales, which is around 6-8C above average for June, with Scotland and Northern Ireland getting into the low-twenties. However, other models keep high pressure to the west or south-west of the UK, which would give more of a north or north-westerly wind, keeping temperatures lower, around the low-twenties Celsius in the south and in the teens further north.
There is certainly a lot of doubt over whether we might reach official heatwave criteria. However, some forecasts suggest temperatures could rise further next week, keeping the prospects of a heatwave on the table.