The UK is poised for a significant heatwave, with temperatures projected to soar to 23°C in at least 14 counties beginning on May 21. Weather forecasts from WXCharts and Netweather.tv indicate that the warm conditions will start to develop on the evening of May 20, with many areas in England expected to reach around 20°C. Regions such as Greater London, Berkshire, and Surrey are anticipated to experience the peak temperature of 23°C. However, before this warm spell, rain is expected, as the Met Office warns of changeable and unsettled weather conditions in the days leading up to the heatwave. The forecast suggests that while some areas may enjoy drier spells, others could face heavy showers. Current temperatures across the UK show a stark contrast, with Plymouth reaching 18°C while Kirkwall in Orkney recorded a low of 9.6°C.