Near-surface humidity was monitored from 2005 to 2010 in a mesoscale network of 232 sites in the foothills of the Rocky Mountains in southwestern Alberta, Canada. The monitoring network covers a range of elevations from 890 to 2880 m above sea level and an area of about 18,000 km<sup>2</sup>, sampling a variety of topographic settings and surface environments with an average spatial density of one station per 78 km<sup>2</sup>. Hourly screen-level temperature and relative humidity were recorded over the study period, forming the basis for daily mean relative humidity and vapour pressure estimates. Hourly air pressure measurements at Calgary Airport are adjusted for elevation to calculate specific humidity from the vapour pressure. Daily mean specific humidity, relative humidity, and vapour pressure from the multi-year study are available at <a href="https://doi.pangaea.de/10.1594/PANGAEA.889435" target ="_blank">https://doi.pangaea.de/10.1594/PANGAEA.889435</a>. This manuscript describes the processing methods used to quality-control and gap-fill the data. Overall data coverage for the study period is 89 %. Inverse-distance weighting techniques are used to estimate the missing 11 % of data, based on neighourhood values of daily mean specific humidity. We report monthly mean lapse rates of specific and relative humidity. Plots of seasonal and spatial humidity patterns illustrate the relations between humidity variables and temperature, elevation, and longitude in the region.