Met Office issues amber heat health alert as summer returns with temperatures set to hit 35°C on WednesdaySummer is making a dramatic return across much of the UK, with temperatures forecast to soar to 35°C by Wednesday. Another spell of intense summer heat is set to grip parts of the UK this week, with temperatures forecast to climb as high as 35°C by Wednesday. The Met Office says high pressure will dominate much of the country through the first half of the week, bringing widespread sunshine and rapidly rising temperatures. Under prolonged sunshine, temperatures could reach 35°C across parts of southeast England, with many other areas widely exceeding 30°C. Elsewhere, fresher conditions will gradually spread southwards from the north, although many southern counties are expected to remain dry.