A rare May snow event is predicted to affect 27 cities in the UK, including London, as an unseasonal cold spell approaches. According to the ECMWF weather model, snow will begin falling in northern Scotland on the evening of May 1, with cities such as Aberdeen, Dundee, and Newcastle being the first to experience flurries. By 6am on May 2, snow is expected to spread to Northern Ireland and coastal areas of Wales, with potential snowfall reaching as far south as Brighton. The heaviest accumulations are projected in Gloucestershire and southern parts of Scotland, while light flurries may reach London by 6pm. The snowfall is anticipated to continue for about 30 hours, with the Met Office indicating that some areas may experience 'wintry' showers during this period.