The data collection contains meteorological, soil and snow measurements from two nearby sites in the forest-tundra ecotone in the Tasiapik valley near Umiujaq in northern Quebec, Canada. One site is on a mixture of lichen and shrub tundra and the data set there comprises 9 years of meteorological, soil and snow data as well as 3 years of eddy covariance data. The other site, 850 m away, features vegetation consisting mostly of tall shrubs and black spruce. There, 6 years of meteorological, soil and snow data are available. In addition to the data from the automated stations, profiles of snow density and specific surface area were collected during field campaigns.This data set comprises heat- and CO2 flux data measurements from the tundra vegetation zone.