Dr Who - its interesting that you used the phrase 'poorer conditions'. I realise the conditions aren't ideal in UK, but as far as UK goes - they don't get a lot better! The day temps are about 23/24C and night temps are 12-14C, they get sun most days (although we have our fair share of cloud) so IMO, the conditions aren't ideal, but I would't describe them as poor either.
You might be getting those kinds of conditions where you are, but my greenhouse is routinely 3 or 4 degrees cooler than that (I got a cheap data logger to see what the temperatures actually are). We also often just have a heavy covering of cloud, although we have been getting the odd sunny interval recently which really makes a difference. Enjoy the sunshine...