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Saint Lawrence River
Saint Lawrence River Current Water Temperature and Forecast
On this page, you will find comprehensive information about the water temperature in Saint Lawrence River, including current readings, historical data and trends, monthly averages, as well as weather forecasts and upcoming temperature predictions. We find every spot where you can swim and tell you what the water temperature is there today and throughout the year.
Current Water Temperature in Saint Lawrence River
17.1°C
TODAY
17.8°C
YESTERDAY
18.1°C
A WEEK AGO
As of today, the minimum water temperature in the Saint Lawrence River ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people.
It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Analysis, Historical Data, and Forecast of Water Temperature
Water Temperature Chart for Saint Lawrence River Over the Last 30 Days
Today the water temperature in Saint Lawrence River is higher than the same day in previous years. The water temperature range here in September is from 11°C to 20°C. The water temperature has decreased over the past 7 days but has increased over the past month.
The forecasted water temperature values for Saint Lawrence River are presented in the table below.
The actual water temperature values near the shore may differ by a few degrees from the stated values. For the development of the forecast, we use our own mathematical model that takes into account the current water temperature changes, historical data, and key weather trends, including wind strength and direction, and air temperature in each specific region.
Daily Water Temperature Chart
| Date | Current | Average | Forecast |
|---|---|---|---|
| Sep 3 | 18.1°C | 15.5°C | |
| Sep 4 | 18.6°C | 15.5°C | |
| Sep 5 | 18.6°C | 15.5°C | |
| Sep 6 | 18.5°C | 15.5°C | |
| Sep 7 | 18.4°C | 15.5°C | |
| Sep 8 | 18.0°C | 15.5°C | |
| Sep 9 | 17.8°C | 15.5°C | |
| Sep 10 | 17.1°C | 15.5°C | |
| Sep 11 | 15.5°C | 16.9°C | |
| Sep 12 | 15.5°C | 16.8°C | |
| Sep 13 | 15.5°C | 16.7°C | |
| Sep 14 | 15.5°C | 16.6°C | |
| Sep 15 | 15.5°C | 16.5°C | |
| Sep 16 | 15.5°C | 16.4°C | |
| Sep 17 | 15.5°C | 16.3°C | |
| Sep 18 | 15.5°C | 16.2°C |
Water Temperature Ranges in Saint Lawrence River by Month
January
| Minimum | Average | Maximum |
|---|---|---|
| 2°C | 5.5°C | 9°C |
February
| Minimum | Average | Maximum |
|---|---|---|
| 2°C | 5.5°C | 9°C |
March
| Minimum | Average | Maximum |
|---|---|---|
| 1°C | 6°C | 11°C |
April
| Minimum | Average | Maximum |
|---|---|---|
| 1°C | 8.5°C | 16°C |
May
| Minimum | Average | Maximum |
|---|---|---|
| 6°C | 13.5°C | 21°C |
June
| Minimum | Average | Maximum |
|---|---|---|
| 11°C | 16.5°C | 22°C |
July
| Minimum | Average | Maximum |
|---|---|---|
| 17°C | 20°C | 24°C |
August
| Minimum | Average | Maximum |
|---|---|---|
| 17°C | 20.5°C | 24°C |
September
| Minimum | Average | Maximum |
|---|---|---|
| 11°C | 15.5°C | 20°C |
October
| Minimum | Average | Maximum |
|---|---|---|
| 8°C | 13.3°C | 16°C |
November
| Minimum | Average | Maximum |
|---|---|---|
| 3°C | 8.1°C | 16°C |
December
| Minimum | Average | Maximum |
|---|---|---|
| 3°C | 4.7°C | 8°C |
Monthly Water Temperature Histogram for Saint Lawrence River
Water Temperature in Cities and Towns on Saint Lawrence River
Saint Lawrence River Weather
SEPTEMBER 10
15°C / 18°C
overcastrain: 1% | wind: 31 km/h
SEPTEMBER 11
13°C / 19°C
light drizzlerain: 12% | wind: 23 km/h
SEPTEMBER 12
7°C / 16°C
overcastrain: 1% | wind: 20 km/h
SEPTEMBER 13
9°C / 19°C
overcastrain: 7% | wind: 11 km/h
SEPTEMBER 14
12°C / 16°C
moderate drizzlerain: 25% | wind: 14 km/h
SEPTEMBER 15
12°C / 21°C
overcastrain: 13% | wind: 22 km/h
Water Temperature in Saint Lawrence River: General Trends and Swimming Opportunities
Source Lake Ontario
• location Kingston, Ontario / Cape Vincent, New York
Mouth Gulf of St. Lawrence / Atlantic Ocean
• location Quebec, Canada
Length 500 km (310 mi)
The Saint Lawrence River, stretching between the United States and Canada, is known for its clear, cold waters that vary greatly in temperature depending on the season. In the summer months, water temperatures typically range from 60°F to 70°F (15°C to 21°C), which can be inviting for swimmers in areas where conditions are safe. However, even during the warmest months, the water remains on the cooler side compared to other rivers, offering a refreshing experience for those seeking relief from the summer heat.
Swimming in the Saint Lawrence River is most popular in designated areas, such as near parks, beaches, and calmer stretches of the river. The Thousand Islands region, in particular, is a favored spot for water activities, offering stunning scenery and generally manageable conditions. However, swimmers should be aware of the river’s strong currents in certain areas, as well as colder temperatures in deeper sections or near the river’s flow into the Atlantic Ocean. Overall, the Saint Lawrence River provides a unique and scenic environment for swimming, best enjoyed in the summer and with proper attention to safety.
Geographical Location of Saint Lawrence River
Frequently Asked Questions About Saint Lawrence River and its Water Temperatures
What is the current water temperature in Saint Lawrence River?
The water temperature today in Saint Lawrence River ranges from 64°F (17.8°C) to 67°F (19.7°C).
What is the water temperature in Saint Lawrence River during the summer months?
The average water temperature in Saint Lawrence River during the summer months is typically between 65°F to 71°F (19°C to 21°C), and it can reach up to 75°F (24°C) at its warmest. However, in some years, the temperature may exceed this range.
What is the water temperature in Saint Lawrence River in May?
The average water temperature in Saint Lawrence River in May ranges from 46°F to 70°F (8°C to 21°C).
What is the water temperature in Saint Lawrence River in September?
The average water temperature in Saint Lawrence River in September is typically between 52°F to 66°F (11°C to 19°C).
Where does Saint Lawrence River flow?
Saint Lawrence River flows through United States (New York), Canada (Quebec, Ontario).
Is it possible to swim in the Saint Lawrence River?
Yes, it is possible to swim in the Saint Lawrence River. However, due to strong currents and water quality, it may not always be safe.
What major cities are located on Saint Lawrence River?
Cities along the course of Saint Lawrence River include Montréal (Quebec), Québec (Quebec), Trois-Rivières (Quebec).