With the generally southerly winds of late, the SST in Mount's Bay has risen nicely, after being particularly low the last week in May. S-SW winds raise the SST in Mount's Bay.
Generally off Cornwall & Devon the SST is now 13.5-14C. Currently 13.5C @ Perranporth, 13.6C @ Looe, 13.7C @ Porthleven. 14.7C at the Penzance Buoy, back to near normal. That's > 2C higher than it was a week ago.
It helps make these humid conditions feel muggy, and means that even out at Sevenstone's the air temperature is 14C in the mist. In Penzance it was 15.2C @ 09:00, it rose to around 17C in a mid morning burst of sunshine. No measurable rain yet, just a damping of mizzle.