Their average July max is around 20C off the top of my head so anything above the mid 20's would be a novelty for them. I remember looking up extremes for London a few years ago out of curiosity and I vaguely remember seeing their alltime record was about 38C... pretty impressive for a place that's 50N. Would be like Macquarie Island getting to 38C in terms of latitude if the ocean currents were the same.

I was actually checking out London's weather a few weeks ago when it was unsettled and max's were around 30C - LI values dipped to an impressive -7 there... pretty extreme for there. Was fun watching the webcams showing all the storms grow and sweep over. Nowhere near as extreme this time around so thunderstorm probabilites look a bit borderline to me.

Ken.