The UK is to be heit by a 21C “mini heatwave” this weekend, according to the latest weather maps. Forecasters at WXCharts say Brits should prepare for warm weather on Sunday, May 12, with the south of the country seeing the best of the weather. East Anglia, London and the Midlands are to see the best of the weather with a chance of temperatures higher than 20C, while almost all of the country will see temperatures in excess of 17C. In the north, the hottest places will be Liverpool, Glasgow and Newcastle which should all see the mercury rise to around 19C, the charts predict. While there will be warmer weather, the period will not officially be a heatwave. The Met Office says a heatwave is a period of at least three consecutive days with daily maximum temperatures meeting or exceeding 25C. For the same period the national forecaster predicted “fine and dry” weather for the majority of Britain. Its forecast for the period between Friday, May 10 and Sunday, May 19, read: “There is …