🇧🇩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) defines three traditional seasons: the hot, humid pre-monsoon (March–May), the southwest monsoon period (June–October) that delivers 60–80% of annual rainfall, and the cooler, drier winter (November–February).

In Dhaka, January averages 19°C while June reaches 30°C; pre-monsoon heat frequently exceeds 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 May–June and October–November.

Major historical events include the 1970 Bhola cyclone (estimated 300,000 deaths), the 1991 cyclone, Sidr (2007), and Aila (2009). Monsoon flooding regularly inundates 30% or more of the country, exacerbated by Himalayan glacial melt and rising sea levels that make Bangladesh among the world's most climate-vulnerable nations.

Our archive covers 2 Bangladeshi cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Dhaka, around 31.1°C, while Dhaka records the coldest January nights near 12.9°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 0.7°C.