Thunder Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Thunder Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Thunder Lake today is 21°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 |
|---|---|---|---|
| JUN 3 | 17.7°C | 18.0°C | |
| JUN 4 | 17.7°C | 18.0°C | |
| JUN 5 | 17.8°C | 18.0°C | |
| JUN 6 | 18.1°C | 18.0°C | |
| JUN 7 | 20.8°C | 18.0°C | |
| JUN 8 | 20.9°C | 18.0°C | |
| JUN 10 | 21.0°C | 18.0°C | |
| JUN 11 | 18.0°C | 20.9°C | |
| JUN 12 | 18.0°C | 20.7°C | |
| JUN 13 | 18.0°C | 20.6°C | |
| JUN 14 | 18.0°C | 20.4°C | |
| JUN 15 | 18.0°C | 20.3°C | |
| JUN 16 | 18.0°C | 20.1°C | |
| JUN 17 | 18.0°C | 20.0°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 | 1°C | 3°C |
| February | 0°C | 1°C | 3°C |
| March | 0°C | 1°C | 3°C |
| April | 1°C | 5°C | 9°C |
| May | 6°C | 12°C | 18°C |
| June | 15°C | 18°C | 21°C |
| July | 18°C | 23°C | 27°C |
| August | 18°C | 24°C | 30°C |
| September | 14°C | 16°C | 19°C |
| October | 9°C | 13°C | 17°C |
| November | 2°C | 8°C | 13°C |
| December | 0°C | 1°C | 3°C |
Thunder Lake: Water Temperature by Location
Thunder Lake: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Thunder Lake in Wisconsin follows the typical seasonal pattern of northern inland lakes. After ice-out in spring, surface temperatures often rise from about 40–60°F (4–15°C). By early summer the lake commonly reaches 60–70°F (15–21°C) and in warm July–August periods surface temperatures are frequently in the 70–80°F range (21–27°C), with shallow bays sometimes warming into the low to mid-80s°F (28–30°C). In autumn the water cools back toward 40–60°F (4–15°C) and by winter the surface will approach freezing, about 32°F (0°C), with stable ice cover on most years. Deeper water stays notably cooler year-round because of stratification and thermoclines, so temperatures can vary substantially with depth and location on the lake.
Swimming is generally allowed as a recreational activity at Thunder Lake where public access or private shoreline permits it, but conditions and rules depend on local ordinances and posted advisories. Water quality testing, the presence of blue‑green algal blooms, boat traffic, underwater hazards and the lack of lifeguards are common factors that affect when and where it is safe to swim. Cold water shock is a real risk in spring and late fall. Visitors should follow beach postings, check current water‑quality notices from local authorities, and use standard safety measures such as swimming with a buddy and wearing a life jacket when boating.