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Water level chart

Data Available


The Canadian Tide and Current Tables - Volume 1-7 are now available for digital download at

The Tide Tables provide predicted times and heights of the high and low waters associated with the vertical movement of the tide. The tide predictions are available in table, graphic and text formats for over seven hundred stations in Canada.

The Current Tables provide predicted times for slack water and the times and velocities of maximum current, all of which are associated with the horizontal movement of the tide.

The times and heights of the high and low waters and the hourly water levels for seven days are also available.

Search Station List

The predicted hours correspond to the time zone of the locality for the year period.

Meteorological conditions can cause differences (time and height) between the predicted and the observed tides. These differences are mainly the result of atmospheric pressure changes, strong prolonged winds or variations of freshwater discharge.


The water level observations are available in table, graphic and text formats for many stations on Pacific, the Great Lakes, their connecting waterways and the St. Lawrence River.



For the Great Lakes, the water levels data are available for a 30 days period (hourly water levels for the current and preceding month):

Lake Superior

Lake Huron - Georgian Bay

Lake St. Clair

Lake Erie

Lake Ontario and St. Lawrence River

For the St. Lawrence River, the water levels are available at intervals of 15 minutes for a period of 24 hours for the following places:

Lac des Deux-Montagnes

St. Lawrence River

St. Lawrence River Estuary

St. Lawrence Maritime Estuary

Gulf of St. Lawrence

Oceanic Forecast

The Oceanic Forecast for the St. Lawrence Gulf and Estuary are issued by the personnel of the Modelling and Operational Oceanography Division of the Canadian Hydrographic Service at the Maurice Lamontagne Institute, Fisheries and Oceans Canada. Data are available on this Web Site:

The surface currents, sea ice and water temperature forecasts for the Gulf of St. Lawrence are extracted from a three-dimensional numerical model computing the oceanic circulation under the influence of tides, the St. Lawrence River fresh water runoff, the atmospheric forcing, and the sea ice drift, growth and melt. The model has been validated under a series of scientific and operational research and development programs within the Department of Fisheries and Oceans Canada. The validation process was done against a number of oceanographic observations including currents, water level, water temperature and salinity, and sea ice drift, concentration, and thickness.


Integrated Science Data Management (ISDM) acquires, processes, quality controls, archives and distributes tide and water level (TWL) data reported on a daily to monthly basis from the DFO Canadian Hydrographic Service (CHS) water level gauging network.

ISDM also operates a Tides and Water Levels Benchmark Database for the Canadian Hydrographic Service where information on the benchmarks from various DFO stations can be found.

As Canada's national data center, ISDM historical tides and water level data archives presently hold over 30 million records with the earliest dating back before the turn of the century. Over 70,000 new hourly height observations and other higher resolution data are added on a monthly basis. Data are also exchanged annually with Environment Canada.

ISDM also participates in the Global Sea Level Observing System (GLOSS) by contributing data from the Canadian network on an annual basis.

Requests for these data, data products and additional information may be made on-line by completing a request form.


The SINECO network is an observation and forecast operated system of water levels covering the whole St-Lawrence Seaway from Montreal to Sept-Iles. The network is operated and governed by the Canadian Hydrographic Service-Quebec Region.

Its principal components are:

  • A network of approximately twenty measurement systems (tide gauges) distributed at strategic points all over the St-Lawrence River;
  • A water level forecast digital system of 0 to 48 hours and of 2 to 30 days including the measured water level data and the environmental data (like the water flow of the tributary rivers);
  • The observed data, forecasts and predictions are all in the database;
  • The visual data interface, known as Oceanus (see chart below).
Oceanus visual data interface
(Click to enlarge)

This integrated system serves primarily the Maritime transport companies working between Sept-Iles and Montreal and more importantly it operates in the shallowest portion of the river located between Quebec city and Montreal. The Canadian Coast Guard uses the SINECO information system for Vessel Traffic Management on the St-Lawrence River. The SINECO network is also used for the planning and execution of the hydrographic survey work and the dredging of the St-Lawrence Seaway. Ship owners may also have access to the SINECO system to insure the optimal freight loading of their vessels.

Mariners can obtain the access to the SINECO data system by contacting the CHS - Quebec Region to obtain a licence. There is a charge to access the SINECO system. For more information about SINECO network, please contact the CHS by E-mail at the following address:, or by phone at (418) 775-0502.