Some of the most challenging and societally important work in the field of climate dynamics lies at the interface between climate and weather: work directed toward understanding the impacts of climate change on the frequency of occurrence, duration, and intensity of significant weather events. With the availability of daily data and computers with enough speed and storage capacity to effectively access them, and climate models with embedded, high resolution grids, it is now possible to undertake much more comprehensive studies of this type than was feasible a decade ago. Types of significant weather considered in these analyses include extreme wintertime cold and summertime heat, early and late frosts, heavy rain and snow, tropical cyclones, severe convective storms, and fog. Types of climatic changes include variations associated with ENSO and the Madden-Julian Oscillation, as well as longer term, human-induced changes associated with stratospheric ozone depletion and greenhouse warming. In some cases, the weather changes simply involve a shift in the frequency distribution of the variable in question that is commensurate with the shift in the climatic mean, while in other cases, more complex interactions come into play that yield a larger weather response to a prescribed change in the mean climate state.