My first encounter with snow bunting was back in the late 1970's up at Inverpolly, western Scotland, followed by sightings in the Cairngorms in the mid 1980's. This is a rare breeding bird in the UK, they normally are found breeding around the Artic from Scandinavia to Alaska, Canada and Greenland, we see more in winter.
In Shetland I was lucky enough to come across one in late May a couple of years ago on Ronas Hill, a superb male. Late May is normal for late spring sightings in Shetland and can occur anywhere in the isles.
This year snow buntings started to appear on the 12 September, with a bird at Lamba Ness. Birds continued to be seen throughout the month will larger numbers on Unst by the 29 September with 60 birds present. Throughout October numbers continued to build again with 120 at Belmont on the 8th, but by November numbers started to fall to 20-30 birds and the last 3 on the 28 November, 8 birds on Yell 30 December was the last of the year, with many birds moved south.
The excellent Nature In Shetland website great for details of sightings of all birds.
The white plumage evokes images of a snowstorm as the birds take flight. Being 70 + miles from the coast we don't come across birds in and around Sheffield, except for a few on migration and these are usually found calling while flying over.
Most snow buntings are found along the coast feeding in open weedy and grassy fields or along shorelines. I have come across flocks at Cleethorpes, Filey, and in Lincolnshire and North Norfolk. and they are normally very confiding . Two races have been identified, Iceland and Greenland / Scandinavia