Just an update, given we're now into June...
Firstly, the information I gave regarding Y Ffoes Ddyfn was incorrect. Geraint Evans got in touch to say that he saw that location in good light, through binoculars, on 20 May and it was still there. He estimates 23rd May as final melt date.
Brown Cove on Helvellyn wasn't present when Terry Abraham flew over it on the evening of 28 May. It was last seen 23 May, but wasn't terribly big. Estimating 27 or 28 May final melting. I've had no reports of anything else on the Lakes' hills, so Brown Cove is likely to be the last.
Terry Abraham said that on his flight of 28 May he saw patches in the 'gullies' of Great Dun Fell and Cross Fell. The gullies referred to are without doubt Middle Tongue Beck on the former, and Kirkdale on the latter. The satellite image of 23 May shows the snow at Middle Tongue Beck quite clearly,
here. Alas cloud obscures Cross Fell's west side in the same picture.
My own view, based upon the temperatures and size of patches, is that it's likely that a remnant of one of these Pennines' patches lasted until today.
What we can say for sure, though, is that The Cheviot definitely has snow. There are three (English) patches extant, and one Scottish. There is a guy going up today to check on these, so I'll hopefully get a fix on them later.