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Changes in both land cover and the atmosphere have impacted the heat fluxes of south Asia in ways that may have altered the timing and magnitude of the monsoon. Century‐long budgets of water and energy in the Krishna Basin (258,948 km²) in southern India demonstrate that irrigation impacted the sensible heat flux of the land surface (H) as much as or more than did the atmospheric brown cloud (ABC) over 1960–2005. Annual discharge of the Krishna River fell from 226 mm during pre‐irrigation land cover (1901–1960) to 64 mm by 1990–2005, when 14–20% of the basin area was irrigated. Over the same period, annual evaporation increased by 166 ± 32 mm (+28%) causing H to decrease by 12.7 ± 2 W m⁻² (−18%) compared to a decrease of 11.2 ± 1.8 W m⁻² caused by the atmospheric brown cloud (ABC). The rate of change in H during irrigation expansion (1960–1990) was between −3.4 and −5.0 W m …