Heidegger's conception of affectivity, as developed for the most part in Being and Time, is reconstructed here with an emphasis on the temporal character of affectivity. While a good number of philosophers of emotion have borrowed from Heidegger's approach, few have so far taken the temporal character of findingness [Befindlichkeit] into account. This paper has three main parts. The first part revisits the standard reading of Heideggerian affectivity, the second reconstructs the conception of "originary temporality' at the core of Division II of Being and Time, while the third section undertakes an interpretation of the way Heidegger construes affectivity as various modes of the "ecstatic temporalizing of Dasein'. The main orientation of the paper is reconstructive. However, some implications for the philosophical study of emotion will be highlighted in the conclusion.