The objectives of this study were to measure and evaluate the energy balance of a snowpack in a northern peatland, with a particular emphasis on the ground heat flux (G), and to evaluate the performance of a point energy and mass balance snowmelt model (SNOBAL) in peatland ecosystems. G is typically considered a small component of the snowpack energy balance (EB) when compared with radiative and turbulent fluxes. However, in environments where the soil temperature remains above freezing throughout the winter, G may be an important energy input to the snowpack. For direct assessment of the role of G in the snow energy budget of such an environment, the EB components of the snowpack at the Mer Bleue bog, a northern peatland, were directly measured and modelled using SNOBAL during the 2009–2010 winter. When integrated over the pre-melt period, simulated and measured G proved to be a large contributor to the EB (25%). Net radiation and G were somewhat under-predicted by SNOBAL, whereas turbulent fluxes (especially latent heat fluxes LE) were considerably over-predicted. G calculated by SNOBAL was found to be sensitive to the temperature gradient between the soil and the lower layer of the snowpack, whereas simulated turbulent fluxes were sensitive to the parameterization chosen to estimate roughness lengths for heat and water vapour. Copyright © 2012 John Wiley & Sons, Ltd.