The δ18O and δ13C records presented here are based on the stalagmite SMT16 collected in São Mateus cave (13.67°S; 46.37°W) located in the Parque Estadual de Terra Ronca (PETER) in central Brazil. This data was presented in the publication by Della Libera et al. (2026). The δ18O and δ13C analyses were performed at the Laboratory of Stable Isotopes at the Institute of Geoscience of the University of São Paulo (LES-USP) and at the Laboratory of Geodynamic, Geochronological and Environmental Studies of the University of Brasilia (LEGGA – UnB). The notation δ in the results refers to the relative Vienna Pee Dee Belemnite (VPDB) standard with the per mil deviation, with uncertainties on the values of 0.1‰. In total, 1320 samples of powdered carbonate were collected along the stalagmite growth axis with a constant spacing of 0.3 mm between samples using a Sherline Mill device with a 0.1 mm drill bit. This dataset provides an average temporal resolution of 8 years per sample.