Plum Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Plum Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Plum Lake today is 20.3°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 24 | 21.5°C | 24.0°C | |
| AUG 25 | 21.3°C | 24.0°C | |
| AUG 26 | 21.3°C | 24.0°C | |
| AUG 27 | 21.3°C | 24.0°C | |
| AUG 28 | 21.5°C | 24.0°C | |
| AUG 29 | 21.6°C | 24.0°C | |
| AUG 30 | 21.6°C | 24.0°C | |
| AUG 31 | 20.2°C | 24.0°C | |
| SEP 1 | 16.1°C | 20.1°C | |
| SEP 2 | 16.1°C | 19.9°C | |
| SEP 3 | 16.1°C | 19.7°C | |
| SEP 4 | 16.1°C | 19.5°C | |
| SEP 5 | 16.1°C | 19.3°C | |
| SEP 6 | 16.1°C | 19.0°C | |
| SEP 7 | 16.1°C | 18.8°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 | 2°C | 4°C |
| February | 0°C | 1°C | 3°C |
| March | 0°C | 2°C | 5°C |
| April | 1°C | 4°C | 7°C |
| May | 6°C | 12°C | 18°C |
| June | 15°C | 18°C | 21°C |
| July | 14°C | 21°C | 28°C |
| August | 18°C | 24°C | 30°C |
| September | 14°C | 16°C | 19°C |
| October | 9°C | 13°C | 17°C |
| November | 3°C | 8°C | 13°C |
| December | 0°C | 2°C | 4°C |
Plum Lake: Water Temperature by Location
Plum Lake: Weather Forecast
September 1
September 2
September 3
September 4
September 5
September 6
Location & Local Information
Plum Lake in northern Wisconsin experiences a wide seasonal range in water temperatures. In spring (April–May) surface temperatures commonly sit between about 40–60°F (4–16°C) as the lake cools out of winter. By summer (June–August) the shallow nearshore water typically warms to roughly 65–78°F (18–26°C), with the warmest readings often in July. In autumn (September–October) temperatures fall back to roughly 50–65°F (10–18°C) as cooling begins, and in winter the lake is usually ice-covered with surface water around freezing, about 32–39°F (0–4°C) beneath the ice depending on conditions and depth.
Swimming is generally allowed during the ice-free months because surface temperatures frequently rise into a comfortable range for recreational swimming, especially in July and August when nearshore areas are warmest. Deep water remains noticeably colder year-round due to stratification, so swimmers should remain near shore and be aware of sudden temperature changes. In winter, swimming is not typical because of ice cover and hypothermia risk; any ice swimming should only be attempted with proper safety measures. Local health and access advisories affect specific swimming sites, so checking current guidance before entering the water is advisable.