perform. plus prince william and duchess katherine are expecting their third child any time soon. and this year's london marathon could be the hottest on record. when we say start, you don't mean start, you mean start. >> symbolically. she'll have a long weekend. she's going to press a big red button and get things going around 10:00 a.m., which by then, things are going to start getting toef inting toasty as f temperatures. we'll talk about how hot we think it's going to get in. this is the way you've been keeping cool. upper 20s the last few days. if you're watching from the united states and that doesn't sound hot, that would be mid and upper 80s. that comes on the heels of very chilly temperatures. we've gone completely the other way. this area of high pressure sinking warm air, compressing down on the surface. very hot temperatures. not just by the way in london