These NetCDF datasets describe potato thermal exposure across Europe using daily mean air temperature. The workflow classifies each daily temperature value into one of seven Thermal Threshold Classes (TTCs), ranging from drastic cold to drastic hot, using potato-relevant temperature thresholds. The resulting counts represent the number of days in each class for each grid cell, year, and, where relevant, phenological stage. The regional growing-season windows used in the analysis distinguish northern, central, and southern Europe. The stage-wise datasets further split the growing season into four phenological stages, allowing thermal exposure to be interpreted during agronomically important periods rather than only as a whole-season summary. This directory contains the whole-growing-season Mann-Kendall trend analysis results for annual TTC frequencies. The file summarizes the direction and p-value of monotonic trends for each grid cell and thermal class.