Janesville — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Janesville, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Janesville today is 20.6°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 |
|---|---|---|---|
| SEP 4 | 21.4°C | 17.0°C | |
| SEP 5 | 20.9°C | 17.0°C | |
| SEP 6 | 21.4°C | 17.0°C | |
| SEP 7 | 20.0°C | 17.0°C | |
| SEP 8 | 20.4°C | 17.0°C | |
| SEP 9 | 21.0°C | 17.0°C | |
| SEP 10 | 19.9°C | 17.0°C | |
| SEP 12 | 17.0°C | 20.4°C | |
| SEP 13 | 17.0°C | 20.2°C | |
| SEP 14 | 17.0°C | 20.1°C | |
| SEP 15 | 17.0°C | 19.9°C | |
| SEP 16 | 17.0°C | 19.7°C | |
| SEP 17 | 17.0°C | 19.5°C | |
| SEP 18 | 17.0°C | 19.3°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 | 5°C | 9°C |
| February | 0°C | 5°C | 9°C |
| March | 2°C | 7°C | 11°C |
| April | 5°C | 10°C | 16°C |
| May | 8°C | 13°C | 21°C |
| June | 14°C | 18°C | 23°C |
| July | 17°C | 22°C | 28°C |
| August | 17°C | 21°C | 25°C |
| September | 11°C | 17°C | 23°C |
| October | 8°C | 14°C | 20°C |
| November | 3°C | 8°C | 16°C |
| December | 1°C | 5°C | 8°C |
Janesville: Weather Forecast
September 12
September 13
September 14
September 15
September 16
Location & Local Information
Janesville, Wisconsin, is located along the Rock River, which flows through the city and offers a variety of recreational opportunities. The water temperature in the Rock River can vary throughout the year, with summer temperatures generally ranging from 60°F to 70°F (16°C to 21°C). Early in the summer, the river tends to be a bit cooler due to spring runoff, but as the season progresses, the water warms up, making it more comfortable for activities like canoeing, kayaking, and fishing.
Swimming in the Rock River in Janesville isn't as common due to the relatively cool temperatures and the river's currents. While some sections of the river have slower-moving water and are suitable for wading or brief dips, the overall water temperature is often too cold for extended swimming. The river's flow can also present challenges, particularly in areas with stronger currents, making it less ideal for casual swimming.
For those seeking a more traditional swimming experience, Janesville offers access to local public pools where the water temperature is kept between 78°F and 82°F (25°C to 28°C). Additionally, nearby lakes, such as the Lake Koshkonong to the north, provide warmer water conditions for swimming, particularly later in the summer when the water in these larger bodies tends to warm up more quickly. While the Rock River is better suited for boating and fishing, it remains a scenic and peaceful spot for outdoor recreation.