ABSTRACTThis study reports on an analysis of a Landsat- 5 TM band 6 image from an October night 1988. With radiosonde data and an atmospheric propagation model definite temperatures are determined. Examples are given of how the imagery can be used for analyses of some hydrological phenomena, like fast radiative cooling of lake water surfaces, and coastal upwelling. The satellite derived temperature patterns on clear-cuts are examined, especially with the relation to elevation, aspect and slope.