environment and climate change canada (eccc)'s climate research division summarized annual precipitation changes, evaluating records up to 2007. they observed: "precipitation has generally increased over canada since 1950 with the majority of stations with significant trends showing increases. the increasing trend is most coherent over northern canada where many stations show significant increases. there is not much evidence of clear regional patterns in stations showing significant changes in seasonal precipitation except for significant decreases which tend to be concentrated in the winter season over southwestern and southeastern canada. also, increasing precipitation over the arctic appears to be occurring in all seasons except summer." changing annual precipitation patterns can affect spring flood conditions on large river systems but would generally not affect flash flooding in urban systems.