🇬🇧United Kingdom

The United Kingdom stretches from 49°55′ to 60°51′N as an island state in the North Atlantic, comprising Great Britain—England, Scotland, and Wales—plus Northern Ireland, covering approximately 243,610 km² with diverse landforms ranging from the rolling lowland English heartland through the Pennines and Lake District uplands to the Welsh massif crowned by Snowdon or Yr Wyddfa at 1,085 m, the Scottish Highlands rising to Ben Nevis at 1,345 m as the highest peak in the British Isles, and the wet northwest of Northern Ireland. The climate is overwhelmingly oceanic Cfb thanks to the moderating North Atlantic Drift and prevailing southwesterly winds, with a slight transition to subpolar oceanic Cfc on the Scottish Highlands and northern islands and a marginally drier, more continental tendency in the lee of the southeast encompassing London and Kent.

London averages 5°C in January and 19°C in July with 590 mm of rainfall evenly distributed year-round. Plymouth on the south Atlantic coast registers 7°C and 17°C with 1,000 mm; Edinburgh cooler at 4°C and 16°C with 700 mm; Glasgow 4°C and 16°C with 1,250 mm; Cardiff 4°C and 17°C with 1,150 mm; Belfast 4°C and 16°C with 850 mm. The Cairngorm summits remain cold at −2°C average with 2,000 mm and reliable winter snow.

The Atlantic storm track delivers frequent depressions year-round with strong gales. Notable events include the October 1987 Great Storm, the January 1990 Burns Day Storm, the December 2013 St Jude's Day event, the February 2014 winter rainfall record, the 2007 summer floods, the 2018 Beast from the East (−14°C), and 40.3°C at Coningsby on 19 July 2022 as the UK's first recorded 40°C.

Our archive covers 1 British cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in London, around 20.9°C, while London records the coldest January nights near 1.8°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.7°C.