Environment Canada provides short-duration ...

Environment Canada provides short-duration rainfall intensity statistics often used for sizing and design of hydrological structures to structurally accommodate and carry water runoff from small catchments. Building roof rain loads and drainage systems, road culverts, and municipal storm sewer systems are examples where rainfall intensity is important. Commonly known as “IDF curves”, the most recent set of IDF tables and graphs for 557 locations across Canada are available in electronic file format for download via FTP. It is important to note that there is considerable variability on a location-by-location basis in the most recent data used to produce this information, as described below.