ROCHESTER, NY (WROC) – The annual average Lake Ontario water level is 245.31 feet. Water levels vary based on many factors that include seasonal rainfall, snow melt, evaporation, drought conditions, flows downstream, and regulations laid out in Plan 2014. This year has been the first in many that levels have dropped below average.
The lake had record flood events in both 2017 and 2019. There have been only a few periods of below average water levels in the last five years, with 2021 so far being one of those years. 2020 did have monthly water levels drop below 245.31 feet, but the yearly average remained higher.
The dark line is 2021, showing the first dip below daily/monthly average since late 2018. (From USACE) The light blue line is 2020. Note how levels neared average from August through the fall and into winter. A dry stretch paired with high outflows helped levels drop.
Lake Ontario water levels are on the far right. Each month remained above average in 2020, 2019, and the last few months of 2018.
Lake Ontario water levels average 245.24′ in September. It was back in September 2018 when water levels were below this point. That makes it almost two and a half years since Lake Ontario has been below average.
As of February 4, Lake Ontario Water Levels currently sit at 244.62″. The last time water levels were this low was back in December 2016.
Expect to see water levels stay within a few inches of current levels for the next month. Outflows should remain high as ice forms downstream. More snow and rain events in April and May will likely result in rising waters.