AbstractAn account (including a literature survey) is given of the factors which determine the water supply and run-off from glaciers during the winter and of the general conditions for this run-off in different environments. Field observations at four valley glaciers in northern Sweden are reported. No evidence of winter run-off was found in the main“summer”streams at some of these normal-sized glaciers. In view of this fact, certain conclusions can be drawn as to the origin of the water running off through some minor streams. This water has more or less the same characteristics as groundwater. The total absence of winter run-off from other glaciers in the same environment cannot be excluded.The temperature development during the winter under snow covers outside the glaciers may be of interest as regards the run-off conditions at the ice-margin. (Furthermore observations of the run-off from glaciers are usually made at some distance from the glacier.) Published and unpublished observations from northern Sweden and from the Alps are discussed in this respect. Delayed and prevented run-off from glaciers is treated, as regards the winter conditions, with the aid of an analogical model. The covariation that exists between the percentage of glacierization and the minimum of winter run-off in the Alps is discussed, and is found to depend in the first place on differences in spring-water contribution. Some terms concerning the thermal characteristics of glaciers are presented in an appendix.The table of contents will be found at the end of this paper, on page 184.