It get's hot here but it's so fucking sticky and muggy. I've never been abroad but I'm told Spain, Greece et al. have a different sort of heat, whereby the temperature can go higher than here, but it's no so muggy. Of course, when it rains here it does chuck it down, avoid coming over during Wimbledon to be sure to miss out on some guaranteed rain lol.
On a side note, it can depend on where you go - as budd81 says it has been real hot in London, and yesterday was the warmest June day on record since 1976, when we had a huge drought... but in the North of England it was a different story altogether:
http://www.thesun.co.uk/article/0,,2-2005280281,00.html