Lac Saint-Jean — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lac Saint-Jean, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lac Saint-Jean today is 9.8°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
❌ As of today, the minimum water temperature ranges from 47°F (8°C) to 50°F (10°C). This is still cool water, suitable only for experienced swimmers or those accustomed to cold water. Swimming in such conditions is possible, but not recommended for prolonged periods. Extra caution should be taken during extended exposure, as the cold water can cause heat loss and lead to hypothermia. For added comfort, special clothing can be used. 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.
Water Temperature Chart Over the Last 30 Days
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| OCT 5 | 12.2°C | 12.0°C | |
| OCT 6 | 12.2°C | 12.0°C | |
| OCT 7 | 12.3°C | 12.0°C | |
| OCT 8 | 11.9°C | 12.0°C | |
| OCT 9 | 10.8°C | 12.0°C | |
| OCT 10 | 10.7°C | 12.0°C | |
| OCT 11 | 10.4°C | 12.0°C | |
| OCT 12 | 9.6°C | 12.0°C | |
| OCT 13 | 12.0°C | 9.9°C | |
| OCT 14 | 12.0°C | 10.0°C | |
| OCT 15 | 12.0°C | 10.1°C | |
| OCT 16 | 12.0°C | 10.2°C | |
| OCT 17 | 12.0°C | 10.4°C | |
| OCT 18 | 12.0°C | 10.5°C | |
| OCT 19 | 12.0°C | 10.6°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 0°C | 3°C | 7°C |
| February | 0°C | 2°C | 5°C |
| March | 0°C | 3°C | 5°C |
| April | 0°C | 5°C | 11°C |
| May | 4°C | 8°C | 15°C |
| June | 7°C | 14°C | 18°C |
| July | 15°C | 21°C | 26°C |
| August | 17°C | 21°C | 25°C |
| September | 11°C | 16°C | 22°C |
| October | 7°C | 12°C | 16°C |
| November | 3°C | 6°C | 11°C |
| December | 0°C | 3°C | 7°C |
Lac Saint-Jean: Water Temperature by Location
Lac Saint-Jean: Weather Forecast
October 13
October 14
October 15
October 16
October 17
Location & Local Information
Lac Saint-Jean, often called the inland sea of Quebec, is a vast body of water located in the Saguenay–Lac-Saint-Jean region. Despite its size and northern latitude, the lake’s relatively shallow nature allows its surface water to warm up significantly during the summer months. In the peak summer season, from mid-June to mid-September, surface temperatures typically range from a comfortable 22∘C to 25∘C (72∘F to 77∘F), with highs occasionally reaching 26∘C (79∘F). Conversely, the winter brings long periods of ice cover, with water temperatures dropping to the range of 0∘C to 5∘C (32∘F to 41∘F).
Swimming is widely permitted and highly popular at Lac Saint-Jean, which is ringed by approximately 42 kilometers of sandy beaches, confirming it as a major recreational destination. Several municipal beaches, such as those in Roberval (Pointe-Scott) and Saint-Prime, are typically supervised by lifeguards during sunny days in the peak summer season, providing a secure environment for swimming. However, it is always wise to respect posted signage and water quality advisories. The lake is also known for the challenging annual Traversée internationale du lac St-Jean, a long-distance swim, underscoring its historical importance for open water activities.