Lake Ontario Water Levels

The following graphic shows the range of average annual water levels on Lake Ontario since 1860; the year that systematic water level recording began.

Sources of Information
For a comparison with present, or recent, lake levels, visit Forecast Lake Levels.  At this site, select Weekly Great Lakes water levels forecast or the Monthly Bulletin of lake levels for the Great Lakes.

The levels in the above graphic are given in meters above international Great Lakes Datum, 1985 (IGLD 1985). The Low Water Datum (LWD), or Chart Datum for the lake is 74.2 meters above IGLD 1985.
Credit: NOAA Great Lakes Environmental Research Lab, Ann Arbor, Michigan