It varies place to place, actually. For us, today just marks the end of number 4, so yes, we await 5 (not necessarily happily). 1 in May, a longer one in June and 1 in July, then one that ends today according to the Hampshire 3 day 27° rule. This one doesn't really feel like one. But the July one ran from 5th to 17th, and had 3 days just over 27°. Had the later 2 of those been .4 of a degree cooler, we would have had 2 heatwaves during that period instead of one protracted one. There must be places locally with lower maxima.
Also, some places have had short bursts of heat outside of our 'heatwaves' here that might have met the criteria, including places that only need to manage 26 for 3 days.
So some people will almost certainly be heading towards #6.
Originally Posted by: Bertwhistle