🇮🇷Iran

Iran spans 25°03′–39°47′N, a large Western and Central Asian country covering approximately 1,648,195 km² bordering the Caspian Sea in the north and the Persian Gulf and Gulf of Oman in the south. The landscape is dominated by the great central Iranian Plateau ringed by mountain barriers including the Zagros chain along the southwest reaching Zard-Kuh at 4,548 m, the Alborz along the Caspian shore crowned by Mount Damavand at 5,610 m (the country's highest peak and the highest volcano in Asia), and the Kopet Dag in the northeast.

The central plateau hosts the vast Dasht-e Kavir and Dasht-e Lut deserts, with the Lut routinely recording the world's hottest land surface temperatures. This topography produces an extraordinary climate range from humid subtropical (Köppen Cfa) on the Caspian shore to hot-summer Mediterranean (Csa) on the western Zagros foothills, hot semi-arid (BSh) and hot desert (BWh) across the plateau interior, cold semi-arid and oceanic climates on the Alborz heights, and ice-cap conditions (EF) on the Damavand summit.

Tehran averages 4°C in January and 30°C in July with 220 mm rainfall concentrated November–April. Mashhad records 4°C and 27°C with 250 mm; Esfahan averages 3°C and 29°C with 130 mm. Ahvaz measures 13°C and 38°C with 220 mm—one of the world's hottest cities, reaching 54.0°C in July 2017. Bandar Abbas (Persian Gulf) averages 18°C and 33°C with 170 mm; Rasht (Caspian coast) records 8°C and 26°C with 1,360 mm.

Tabriz averages 0°C and 27°C with 290 mm and snowy winters; Damavand peak remains at −18°C. The Lut Desert regularly records surface temperatures exceeding 80°C. Major events include 2019 Golestan and Khuzestan floods, multi-year droughts (1998–2001, 2020–2023), summer heatwaves in Khuzestan, dust storms, 2018 Karun and Karkheh river floods, Lake Urmia desiccation (~90% loss since 1990s), and Caspian sea-level variations.

Our archive covers 1 Iranian cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Tehran, around 30.8°C, while Tehran records the coldest January nights near −9.1°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 2.4°C.