The first heatwaves of 2023 in Belgium and the UK have been officially declared.
Due to the Urban Heat Island effect, extreme high temperatures are felt most in cities rather than the surrounding rural areas.
In Belgium, the Royal Meteorological Institute (RMI) predicts that the temperature will not go below 25 degrees this week. It is likely that the temperatures will remain high because a high-pressure zone stretching from Iceland to Russia is still determining the weather. In the 15-day forecast, RMI mentions a period in which “the instability due to a southwesterly current could increase”, but in which it “remains warm, with maximum of 24 to 27 degrees in the centre of Belgium.”
It is anticipated that the record for the longest heatwave ever in Belgium could be broken. The heatwave record dates back to 1947 and it lasted 19 days – from 10 to 28 August. The second longest heatwave period was in 1976 and that lasted 17 days.
In the United Kingdom, the UK Health Security Agency (UKHSA) in association with the Met Office issued the first Yellow Heat-Health Alert of the year on the 7 June 2023 as parts of the UK were set to be hotter than Ibiza in Spain. This initial alert was issued on Wednesday for six regions of England, London, the East Midlands, West Midlands, East of England, South East and South West. On the 8 June 2023, the heat-health warning was upgraded to Amber for West Midlands, East Midlands, East of England, South East and South West. The amber level meant that the impact was likely to be felt amongst the wider population and not just the most vulnerable. A yellow alert was issued for the North East, North West and Yorkshire and Humber regions. These initial amber and yellow alerts lasted between the 7 and 12 June 2023.
The alerts were extended, with a Yellow Heat-Health Alert issued for the period 13 - 19 June 2023 in the regions of London, the East and West Midlands, North East, North West, South East, South West, East of England and Yorkshire and Humber.
Sources: KMI - Met Office - Silent Spring Consultants Ltd