🇧🇩Bangladesh

Bangladesh lies between 20°34′N and 26°38′N in South Asia, occupying the Ganges-Brahmaputra-Meghna delta, the world's largest river delta. Most of the country sits below 12 meters elevation, with only the southeastern Chittagong Hill Tracts rising to modest heights (Mowdok Peak reaches approximately 1,052 m). The tropical monsoon climate (Köppen Am/Aw, humid subtropical in the north) defines three traditional seasons: the hot, humid pre-monsoon (March–May), the southwest monsoon period (June–October) that delivers about 80% of annual rainfall, and the cooler, drier winter (November–February).

In Dhaka, January nights drop to about 13°C while June highs reach about 33°C; pre-monsoon heat can exceed 40°C, with violent nor'wester thunderstorms (kalbaishakhi). Annual rainfall varies from 1,500 mm in western districts to over 5,000 mm in the northeast near Sylhet and Lalakhal. Bay of Bengal cyclones strike predominantly in April–May and October–November.

Major historical events include the 1970 Bhola cyclone (an estimated 300,000–500,000 deaths), the 1991 cyclone, Sidr (2007), and Aila (2009). Monsoon flooding regularly inundates large parts of the country, and rising sea levels make Bangladesh among the world's most climate-vulnerable nations.

Our archive covers 55 Bangladeshi cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Pār Naogaon, with average highs around 31.9°C, while Dinajpur has the coldest January nights, with average lows near 11.3°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 0.8°C.