I think 30C will be reached at some point this summer (or early autumn). My complete guess is July 23rd.
I find the current conditions of the last few days to be warm enough, especially when I'm working. Walking miles a day in direct sunlight becomes miserable when the temps go above about 22C. I remember working all day in a heat wave (cant remember when exactly) in the concrete jungle, no shade whatsoever. Must have been close to 30C. I had a completely cold shower when I got home and the water actually felt decently warm I was that hot. Not again, thanks.
Hard work in 30C is murder, sitting in the shade in a beer garden at 30C is marvellous. It's all about activity.