When dealing with the indoor microclimates of cultural and historical heritage cult buildings, it is important to know the types of these buildings by their spatial volumes and by the types of enclosing structures, and it is also important to understand the moisture transfer processes in these buildings, which would allow one to generate solutions on how to more effectively control the indoor microclimate. Due to the antiquity and specific load of these buildings, the existing standards are not applicable. This study summarizes 275 churches in Latvia, dividing them both according to five spatial volumes and according to the types of the materials used, which makes it possible to create potential air flows for all spatial volumes and to predict condensation risks in the future. Additionally, the results of temperature and humidity measurements in two different churches from one region of Latvia are given and the absolute humidity was calculated, and the data were analyzed depending on the outside air temperature. These measurements have yet to be followed up with the data of a full year.