KarsTS 2.4.1 KarsTS is an R-based code with a GUI designed to analyze microclimatic time series with an emphasis on underground environments, such as caves; nonetheless, it can be useful in many other fields of research. KarsTS was born as a package for time series gap filling and thus, it offers multiple univariate and multivariate gap filling tools. However, as KarsTS was intended to be a self-sufficient program, it soon grew to encompass several tools for linear and nonlinear time series analysis, preprocessing and plotting. In particular, KarsTS includes several tools for recurrence analysis. For further information, please, check the User's guide, which is located in the folder inst/extdata.