Britain and Italy are both expected to experience their fourth heatwave of the summer next week, following a weekend of rain and thunderstorms that will provide only a temporary break from the hot and dry conditions. In the UK, temperatures could peak at 35C in central and eastern England by Tuesday before spreading northwards and westwards, according to BBC Weather. In Italy, meteorologists at iLMeteo.it forecast 39C in Milan and Rome, with peaks exceeding 41-43C in the hottest areas of the centre and south, and the return of the African anticyclone from Wednesday 29 July.

Yellow heat health alerts are currently in effect across parts of the East Midlands, West Midlands, South East, South West, East of England, and London until Sunday morning, the Met Office confirmed. More than 20 million Britons are already under a hosepipe ban as water companies clamp down on use following the exceptionally dry and hot weather. In Italy, the Mediterranean Sea has reached 28C off the Ligurian and Tyrrhenian coasts and 30C in Campania, values that Lorenzo Tedici, meteorologist at iLMeteo.it, described as “typical of Cuba or the Caribbean” and a reservoir of fuel for thunderstorms.

Emma Howard Boyd, chair of the independent National Heat Risk Commission (NHRC), said the stifling temperatures are not a one-off, warning: “This is something that we are going to see happening again and again.” She said the heatwave should “absolutely” act as “a wake-up call” for Britain to upgrade its infrastructure to withstand higher temperatures alongside work to tackle carbon emissions. The UK has already experienced three heatwaves this summer, with the third ending in most areas last weekend when cooler air arrived, dropping maximum temperatures widely to 20-24C. However, it persists in some locations such as Usk, Monmouthshire, and Exeter Airport, Devon, where temperatures have exceeded heatwave thresholds for 19 consecutive days.

The weekend will see rain and showers in the north and west of the UK, but Met Office chief meteorologist Dan Suri said that “for much of southern England, dry conditions are expected to remain the dominant feature, with temperatures recovering quickly next week and the potential for very warm or locally hot weather to return.” In Italy, Sunday is expected to bring the heaviest rain, with models identifying a zone of maximum alert along the coasts of Liguria di Levante, Tuscany and Lazio, and instability spreading from the Po Valley and Alps as far as Campania. The heatwave is expected to last at least until 10 August, according to iLMeteo.it, though some brief unstable spells on the Alps are possible.