Synoptic studies of precipitation regimes suggest a 15 percent decrease in snowfall rates over much of Greenland since 1963. However, there has been an increase in snowfall in northeastern Greenland and longer term trends towards greater snowfall over Antarctica (5 percent between 1955-65 and 1965-75). Alpine glaciers in Washington have been in retreat since the early 1980s.
During the past two decades, for example, there appears to be a significant retreat of the snow line in winter and spring, with the annual snow/rain ratios in southern Canada decreasing by 0.7 percent/decade over the past 40 years.