Temperatures are set to hit 30C this weekend, leading many to believe that the UK is at the beginning of a coming heatwave. But while it could be the warmest start to the month on record, experts say the truth is less clear.
The Met Office definition of a heatwave is three consecutive days of temperatures exceeding the “heatwave threshold”, which varies across the country.
For this reason, Met Office meteorologist Michael Silverstone says it looks “unlikely” the UK will reach a heatwave this week, meaning the UK Health Security Agency will not issue a heat-health alert.
The threshold is 25C for most of the UK, with slightly higher numbers for the South and East and rising to 28C in London.
Mr Silverstone said: “Based on the definition of a heatwave, it looks unlikely that we’ll reach one this week.
“Admittedly, it could be close for a few places in the South, though, with temperatures either today or Friday only just failing to exceed the required threshold.”
Temperatures reached 24.9C in Ross-on-Wye, Herefordshire, on Tuesday. Other areas in London and the South saw around 24C.
Mr Silverstone said: “Today, temperatures are set to reach around 27C, maybe even 28C, then climbing to 29C or even 30C tomorrow.
“If we reach 30C on Thursday May 1, it will be the earliest date in May that the UK has seen 30C since our records began in 1860.”
Temperatures are expected to ease by Friday, and Saturday will bring cooler conditions of 14C to 18C across the UK.
The beginning of the month is more likely to be a ‘mini-heatwave’ rather than an actual one, with the Met Office calling it an “early dose of summer.”
The weather service has also urged anyone tempted to swim in the sea this weekend to bear in mind that warmer weather won’t necessarily mean that waters are heating up too. Gareth Morrison, Head of Water Safety for the RNLI said: "With the warm weather forecast this week, we want to remind everyone to stay safe when visiting the coast.
“Whilst the air temperature will be high, water temperature [can] remain dangerously cold. If possible, choose a lifeguarded beach and swim between the red and yellow flags.”
The weekend heat is set to be so sweltering that a broadband provider has issued a warning to people to not leave their internet routers out in bright sunlight.
