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Saint Lawrence Freeze Up Date Outlook

National Weather Service Buffalo NY

830 PM EDT Thu Nov 2 2023



...FREEZE-UP DATE OUTLOOK FOR THE SAINT LAWRENCE RIVER...



The date of the first freeze-up on the Saint Lawrence River near 

Massena, NY is forecast to be January 5, 2024.



WATER TEMPERATURES...



Water temperatures through the first half of October were well above 

average following a stretch of very warm weather in the first week 

of the month. Water temperatures then fell to near average by the 

start of November as more seasonable weather returned to the eastern 

Great Lakes much of the time through the remainder of the month.  



Water Temperatures November 2nd:



Alexandria Bay, NY   55F (normal 54F) 



LAKE ONTARIO OUTFLOW...



The outflow from Lake Ontario has averaged about 267,000 CFS through 

late October and the start of November, which is above the long term 

average. Above average outflow from Lake Ontario is expected to 

continue through the rest of November.



Above average outflow from Lake Ontario results in faster current in 

the Saint Lawrence River, which can delay the onset of shore to 

shore ice.



AIR TEMPERATURES...



Temperatures in the first week of October were very warm throughout 

the eastern Great Lakes, running 15 to 20 degrees above average most 

days. Seasonable temperatures then returned for the second and third 

weeks of October, with most days near or slightly below average. A 4 

day stretch of very warm temperatures returned during the fourth 

week of the month before below normal temperatures arrived for the 

last few days. Despite long stretches of near to slightly below 

average temperatures, the above average days were exceptionally 

warm, allowing for monthly temperature departures to be well above 

average. 



October Average Air Temperatures through October 31st: 



Watertown, NY   53.1F (4.3F above normal) 

Massena, NY     52.5F (5.0F above normal)



FORECAST FOR THE REST OF NOVEMBER...



Air temperatures are forecast to be near to slightly below average 

through the first half of November, with near average temperatures 

favored for the second half of the month. A moderate to strong El 

Nino pattern will continue through the winter, which favors 

increased odds of above average temperatures in the eastern Great 

Lakes and Saint Lawrence Valley.



Given the above factors, the first freeze-up on the Saint Lawrence 

River near Massena, NY is forecast to be January 5, 2024. This date 

is almost two weeks later than the long term average. 



NOTE: Once the water temperature drops to the mid 30s, ice cover can 

develop in just one very cold, calm night.



NOTE: This forecast is for the first shore to shore freeze-up of the 

Saint Lawrence River near Massena, NY. The first permanent shore to 

shore ice often occurs several weeks later.



$$



HITCHCOCK