Something that confuses me is that, year-on-year, average annual temperatures don't vary much. But then you get a Summer like we've had so you'd expect a harsh Winter with very low temperatures to balance things out?
But there's no sign of that?

That suggests a level of 'fairness' or balance in the universe Darren, which doesn't really exist in individual areas... we have a maritime climate which means its always been extremely changeable, plus with climate change on top, the weather here is even less predictable than it used to be, though you can assume that whatever the weather IS doing at any time, it will be more extreme than it used to be in terms of cold, heat, wind, rain. I remember a time when we never, ever had thunder in winter for instance...and never had high winds in May or June, that's changed in the last 15 years.

BarbaraK - whenever I cut back the lavender, I always remove about an inch of topgrowth as well (provided there's enough) even in October, as much as anything to keep it a nice rounded shape, as well as discouraging lots of woody growth left at the base for as long as possible. Usually gets done twice a year, once in summer after flowering and again in late October.

I do the same as Bamboo. The lavender flowered twice, tho' not so profusely the second time.