🇸🇪Sweden

Sweden's climate stretches across three broad zones: a temperate south shaped by the Baltic and the North Atlantic Current, a humid continental centre, and a subarctic north that crosses the Arctic Circle. The Gulf Stream keeps the country noticeably milder than other regions at the same latitude, yet the north–south gradient is sharp in winter and surprisingly narrow in summer.

January ranges from highs near 3°C with nights just below 0°C in the far south to nights around −18°C in the northern interior, where cold snaps can reach −30 to −40°C. Summers are short but mild, with July highs around 23°C in Malmö and 21°C in Haparanda, a difference of only about two degrees across the country. Annual precipitation is typically 500–800 mm, rising above 1,000 mm on the southwest coast and to roughly 2,000 mm in the northern mountains; late summer and autumn are the wettest seasons.

Our archive covers 12 Swedish cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Västerås, with average highs around 22°C, while Umeå has the coldest January nights, with average lows near −8.1°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.8°C.