This study introduces a new method to derive adjusted water vapor (H₂O) climatologies for the upper tropopshere and lower statosphere (UT/LS) using data from 60 000 flights under the IAGOS program. Biases in the IAGOS water vapour dataset are adjusted, based on the more accurate IAGOS-CARIBIC data. The resulting highly resolved H₂O climatologies will contribute to a better understanding of the H₂O variability in the UT/LS and its connection to various transport and mixing processes.