UK weather: Temperatures to hit 35°C in fourth heatwave of the year - here's when it will endThe UK is bracing for its fourth heatwave of the summer, with temperatures expected to soar to 35°C by midweek. However, while the hottest weather is only just arriving, forecasts already reveal when fresher conditions will begin to replace the intense heat. Another spell of hot summer weather is set to grip much of the UK this week, with temperatures climbing rapidly through Tuesday before peaking at around 35°C on Wednesday. Another spell of hot summer weather is set to grip much of the UK this week. Forecasts indicate temperatures could reach 35°C across southeast England, with many other parts of central and southern England exceeding 30°C.