Access monthly historical Great Lakes means data relative to IGLD:Lake SuperiorLakes Michigan/HuronLake St. ClairLake ErieLake OntarioMontreal HarbourAccess Monthly Historical Great Lake Means relative to Chart DatumGraphs of Monthly and Yearly Historical Mean Water Levels by Lake (PDF, 376 KB)This PDF contains a series of line graphs showing the Great Lakes water level data by station. The raw data is also found on the web pages in this section.
