Snow patches in Scotland

Long-lying snow patches in Scotland have been noted from at least the 18th century, with snow patches on Ben Nevis being observed well into summer and autumn. Indeed, the summit observatory, which operated from 1883 to 1904, reported that snow survived on the north-east cliffs through more years than it vanished.

More recently, additional and methodical field study on the subject has been carried out by others, most notably by ecologist Dr Adam Watson. Most of this work concentrated on the mountains of north-east Scotland (in particular, the Cairngorms), but more recent observations by him and others has shed light on various locations throughout Scotland where long-lying snow persists. The available information systematically gathered by observers over the last 50 years or so, and greatly increased since the 1990s, has built up a level of knowledge that points to Scotland’s snow patches being now amongst the best documented in the world.

There are many locations on the Scottish mountains where snow lies regularly into July, August and even September, but the two main areas where snow virtually always lies longer than anywhere else are the Cairngorms and the Lochaber mountains. These areas contain all of Scotland's mountains in excess of 4,000 feet (1,219 m), including Ben Nevis.

In some years snow can persist all summer, in some locations lasting through to the next winter. In 2015 some 73 patches were still present in late November at a time when the next winter's snows had started accumulating. The last time so many patches had survived all year was 1994.

Other locations where snow has been known to survive:

As well as containing five of Scotland's highest mountains, the Cairngorms are the range where snow persists longest, and in more locations, than anywhere else in the UK. Ben Macdui, Cairn Gorm and Braeriach all contain long-lying patches that have been observed for many years.

On Ben Macdui, snow has been known to persist at a few locations from one winter to the next, but the location where more survivals have been noted than any other is grid reference NH994010, close to the Garbh Uisge Beag, which drains into Loch Avon. This patch sits at an altitude of 1,060 metres (3,478 ft).

...
Wikipedia