🇬🇧United Kingdom

The United Kingdom stretches from 49°52′ to 60°51′N as an island state in the North Atlantic, comprising Great Britain (England, Scotland, and Wales) plus Northern Ireland, covering approximately 244,000 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 mostly hilly 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 sees January highs of 8°C with nights of 3°C and July highs of 24°C with 590 mm of rainfall evenly distributed year-round. Plymouth on the south Atlantic coast registers January highs of 9°C (nights 4°C) and July highs of 20°C with 1,000 mm; Edinburgh cooler at 7°C (2°C) and 19°C with 700 mm; Glasgow 7°C (2°C) and 20°C with 1,250 mm; Cardiff 9°C (3°C) and 22°C with 1,150 mm; Belfast 8°C (2°C) and 20°C with 850 mm. The Cairngorm summits remain cold, with winter highs around −1°C, lows around −5°C 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 October 2013 St Jude's Day storm, the record-wet winter of 2013–14, 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 104 British cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Barking, with average highs around 21.5°C, while Burnley has the coldest January nights, with average lows near 0.8°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.5°C.