You obviously did not read my post in its entirety - I also said half of all June days were warmer than 20C, and the average daytime temperature was nearly 1 degree above the long-term average. That's right - the average daytime temperature was warmer than average - meaning the temperatures you actually experienced during the day were warm! In fact, the final 15 days of the month were downright lovely - no cool weather to speak off, and virtually no rain whatsoever. Consistently in the 20-23C range, and the wind eventually abated, meaning it felt pretty oppressive at times due to the higher humidity.
PS - I was one of those who commented on how poor June was - but June changed for the better, and the warmer to thirds of the month cancelled out the cooler third, easily.