We compare column-averaged dry-air mole fractions of water vapor (XH₂O) retrievals from the COllaborative Carbon Column Observing Network (COCCON) with two co-located ground-based spectrometers as references at two boreal sites. Our study supports the assumption that COCCON also delivers a well-characterized XH₂O data product. This is the first published study applying COCCON for MUSICA IASI and TROPOMI validation.