Data from Enhanced late Miocene chemical weathering and altered precipitation patterns in the watersheds of the Bay of Bengal recorded by detrital clay radiogenic isotopes in Paleoceanography and Paleoclimatology. Marine sediment samples from the late Miocene (approximately 9 to 5 million years ago) were taken from International Ocean Discovery Program (IODP) Site U1443 located on the top of the Ninety East ridge in the southern Bay of Bengal. Samples were taken along the composite sediment section or splice and the age model based on shipboard calcareous nannofossil biostratigraphy and magnetostratigraphy was refined using the stable carbon isotopes of benthic foraminifera. The detrital silicates of the clay size fraction were isolated and measured for their radiogenic Sr, Nd, and Pb isotope composition by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) to investigate the provenance of clays produced by weathering in the surrounding watersheds.