Despite the importance of the aging process, there is great disparity in the hygrothermal conditions in which to carry it out. The aim of this work is to propose contrasted data, based on successful cases and millions of experimental data, which can be taken as a reference for the climate control of aging rooms. For this purpose, the hygrothermal environment of 19 red wine aging rooms with multiple construction designs was monitored and statistically characterized. The results showed a great variability in the hygrothermal environment. Frequency histograms and psychometric diagrams revealed the true hygrothermal environment of red wine aging rooms. There were large differences in stability and uniformity depending on the construction design (up to four times). The indoor hygrothermal environment was not kept within the comfort ranges mentioned by a wide list of authors (2–65% of time out of range). A contrasted psychometric diagram establishing monthly comfort intervals and other useful data (stability, uniformity …) were proposed, based on the hygrothermal environment of wineries with quality wines. The results should be a valuable tool for the wine sector, in order to control the evolution of aging, set the programming of air conditioning equipment and simulate the behavior of new wineries.