The publicly available R package aiRthermo is presented in this study, which allows the user to process information relative to atmospheric thermodynamics, ranging from calculating the density of dry or moist air and converting data between moisture indices to processing a full sounding, obtaining factors such as the convective available potential energy, additional instability indices, or adiabatic evolutions of particles. The package also provides the possibility to present information using customisable Stüve diagrams. Many of the functions are written inside a C extension to ensure that the computations are fast. The results of applying this package to five years of real soundings measured over the Iberian Peninsula are also presented as an example. The package considerably extends the capabilities of R to process atmospheric soundings or model results. This will be useful for many practical environmental forecasting applications at different scales, such as statistical downscaling for climate analysis, quantitative precipitation forecasting (particularly precipitation extremes), diagnosing storms, flash floods, and lightning, and in aviation and other fields where computing atmospheric convection and its related parameters is important.The authors acknowledge funding from project CGL2016-76561-Rof the Spanish National Research project (MINECO and FEDER, UE).Santos J. González-Rojí is supported by a FPI postdoctoral researchgrant (MINECO BES-2014-069977). Additional funding was providedby EOLO GIU17/02 (University of the Basque Country, UPV/EHU). Theupper air reports provided by the server run by the University ofWyoming, Dept. of Atmospheric Science, are greatly acknowledged.Constructive comments by two anonymous reviewers and the editor have improved our manuscrip