In the Montreal area, eddy covariance flux towers have been recording sensible and latent heat fluxes, as well as CO2 exchange and standard meteorological data continuously since late 2007 over a rural area, a low-density, single-housing residential area and a high-density, row building residential area located on a West-East transect. An inter-site comparison of wintertime measurements is being conducted to focus on the role of snow and anthropogenic heat release on the energy budget over Montreal. More specifically, the influence of snow removal practices and house heating is being investigated. These results, along with other observations, will be used to validate an urban surface parameterization scheme, based on the Town Energy Balance (TEB) model, coupled to the SVAT Interaction Soil-Biosphere-Atmosphere (ISBA) model. This presentation will provide the first results from the winter 2007-08 measurement period in Montreal.