Episode three of The Great British Weather is all about the sun and the unique role it has, not just in our weather, but also the entire planet's. Live from Greenwich Park, the home of The Royal Observatory, Alexander Armstrong, Chris Hollins and Carol Kirkwood examine how the glowing ball in the sky controls our seasons, our climate and, of course, our temperature. Craig Revel Horwood investigates the history of sunbathing, and the darker side of the sun's summer heat is also put under the spotlight. Why does the South East of England have more thunderstorms than anywhere else in the country, especially in summer? The programme discovers how lightning is actually formed, and gives viewers the definitive survival guide for coping with nature's deadliest display.