Multi-temporal synthetic aperture radar (SAR) metrics are investigated to assess their capability for mapping land cover types. The temporal variability and the minimum backscatter in a time series of Envisat Advanced SAR (ASAR) Wide Swath Mode (WSM) backscatter measurements present unique features over water surfaces with respect to other land cover types. A simple thresholding algorithm applied to these metrics is then presented to detect water bodies. Results from six study areas in Europe and Central Siberia show consistency of the behavior of the multi-temporal metrics over “water” and “land” areas regardless of the specific region. Water body detection accuracies are mostly above 90%, omissions occurring when a water body has a size similar to the pixel size of the SAR image.