Image source, EPA/Shutterstock Image caption, Temperatures exceeded 37C in the heatwave in late June BySimon King Lead Weather Presenter Published 4 minutes ago The third heatwave of the year has started across parts of the United Kingdom with temperatures expected to rise up to 34C for some by the middle of the week. This heatwave is not likely to be as extreme as the one in late-June where we saw the temperature peak at 37.7C, however, it is going to last longer.