Lake Rosseau — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Rosseau, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Rosseau today is 23°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 68°F (20°C) to 74°F (23°C). The water is warm and pleasant for swimming, and in this range, one can stay in the water for extended periods without the risk of hypothermia. This is the ideal temperature for relaxation, swimming, and water sports. Families with children, as well as outdoor enthusiasts, will enjoy swimming and time spent in the water. For most people, this is the optimal temperature for a comfortable beach experience. 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 |
|---|---|---|---|
| AUG 4 | 21.1°C | 23.5°C | |
| AUG 5 | 21.2°C | 23.5°C | |
| AUG 6 | 21.2°C | 23.5°C | |
| AUG 7 | 20.5°C | 23.5°C | |
| AUG 8 | 21.3°C | 23.5°C | |
| AUG 9 | 21.4°C | 23.5°C | |
| AUG 10 | 22.0°C | 23.5°C | |
| AUG 11 | 23.0°C | 23.5°C | |
| AUG 12 | 23.5°C | 23.0°C | |
| AUG 13 | 23.5°C | 23.1°C | |
| AUG 14 | 23.5°C | 23.1°C | |
| AUG 15 | 23.5°C | 23.1°C | |
| AUG 16 | 23.5°C | 23.1°C | |
| AUG 17 | 23.5°C | 23.2°C | |
| AUG 18 | 23.5°C | 23.2°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 | 6°C |
| February | 0°C | 4°C | 7°C |
| March | 0°C | 3°C | 6°C |
| April | 0°C | 7°C | 14°C |
| May | 3°C | 13°C | 22°C |
| June | 10°C | 17°C | 24°C |
| July | 16°C | 22°C | 27°C |
| August | 18°C | 24°C | 29°C |
| September | 17°C | 21°C | 25°C |
| October | 13°C | 16°C | 18°C |
| November | 3°C | 9°C | 13°C |
| December | 1°C | 5°C | 8°C |
Lake Rosseau: Water Temperature by Location
Lake Rosseau: Weather Forecast
August 12
August 13
August 14
August 15
Location & Local Information
Lake Rosseau, located in Ontario’s Muskoka region, is one of the province’s most famous and picturesque lakes, known for its deep, clear water and scenic granite shores. Because of its size and depth, the water temperature in Lake Rosseau varies greatly by season. During winter, the lake freezes partially, and surface temperatures hover near 0 °C (32 °F). In spring, as the ice melts, the water remains cold, typically between 5–10 °C (41–50 °F). By midsummer, the surface warms to about 19–24 °C (66–75 °F), while deeper layers stay much cooler, often below 12 °C (54 °F). In autumn, temperatures gradually fall back to around 10–15 °C (50–59 °F) before the onset of winter again lowers the surface to freezing levels.
Swimming in Lake Rosseau is very popular during the warmest months, from late June through early September, when surface temperatures reach comfortable levels. The lake’s exceptional water clarity and scenic surroundings make it ideal for swimming, boating, and other water sports. Public beaches and private cottages provide convenient access, with calm bays offering safe areas for recreational swimming. Outside the summer season, the cold water makes swimming unsafe and uncomfortable, though Lake Rosseau remains a year-round attraction for nature lovers and photographers.