July is the bottom of the swell curve. The Atlantic is quiet and the systems that feed this coast sit further north, so days pass with nothing on the forecast until a small pulse arrives and everyone is in the water for it.
12°C does not change the wetsuit, it changes how long you last in it: four hours instead of ninety minutes. Put eighteen to twenty hours of daylight on top and July gives you more comfortable time in the sea than any other month of the year, and the least to do with it. Which of those two matters more to you is the whole decision about coming in July.
