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We used cosmogenic nuclide and geochemical mass balance methods to measure long-term rates of chemical weathering and total denudation in granitic landscapes in diverse climatic regimes. Our 42 study sites encompass widely varying climatic and erosional regimes, with mean annual temperatures ranging from 2 to 25 °C, average precipitation ranging from 22 to 420 cm·year⁻¹, and denudation rates ranging from 23 to 755 t·km⁻²·year⁻¹. Long-term chemical weathering rates range from 0 to 173 t·km⁻² year⁻¹, in several cases exceeding the highest granitic weathering rates on record from previous work. Chemical weathering rates are highest at the sites with rapid denudation rates, consistent with strong coupling between rates of chemical weathering and mineral supply from breakdown of rock. A simple empirical relationship based on temperature, precipitation and long-term denudation rates explains 89 …