Lake Wilhelm — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Wilhelm, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Wilhelm today is 22.6°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 |
|---|---|---|---|
| JUN 23 | 21.0°C | 20.5°C | |
| JUN 24 | 21.0°C | 20.5°C | |
| JUN 25 | 21.0°C | 20.5°C | |
| JUN 26 | 21.0°C | 20.5°C | |
| JUN 27 | 21.4°C | 20.5°C | |
| JUN 28 | 21.5°C | 20.5°C | |
| JUN 29 | 22.2°C | 20.5°C | |
| JUN 30 | 22.2°C | 20.5°C | |
| JUL 1 | 25.0°C | 22.7°C | |
| JUL 2 | 25.0°C | 22.8°C | |
| JUL 3 | 25.0°C | 23.0°C | |
| JUL 4 | 25.0°C | 23.1°C | |
| JUL 5 | 25.0°C | 23.2°C | |
| JUL 6 | 25.0°C | 23.3°C | |
| JUL 7 | 25.0°C | 23.4°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 | 1°C | 5°C | 9°C |
| April | 6°C | 11°C | 16°C |
| May | 12°C | 17°C | 22°C |
| June | 17°C | 21°C | 24°C |
| July | 23°C | 25°C | 27°C |
| August | 21°C | 25°C | 29°C |
| September | 19°C | 22°C | 25°C |
| October | 13°C | 16°C | 19°C |
| November | 5°C | 10°C | 14°C |
| December | 1°C | 5°C | 8°C |
Lake Wilhelm: Water Temperature by Location
Lake Wilhelm: Weather Forecast
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Location & Local Information
Lake Wilhelm, a reservoir in northwestern Pennsylvania, experiences typical temperate-lake seasonal swings in surface temperature. In spring the water commonly ranges from about 45–65°F (7–18°C) as it warms after ice-out; in summer surface readings often reach 70–80°F (21–27°C) on warm days, with shallow bays sometimes a few degrees warmer. Early fall generally cools to roughly 60–70°F (16–21°C) before dropping more sharply in late fall and winter, when temperatures approach near-freezing conditions around 32–45°F (0–7°C) and ice can form. Deep or shaded parts of the reservoir remain colder year-round, and recent weather, wind, and inflows can shift these ranges locally.
Swimming at Lake Wilhelm is generally a summer activity when water temperatures are comfortable, but it is subject to park rules and safety considerations. Public access areas are intended for bathing when conditions are safe, yet swimmers should be aware that many lake beaches are unsupervised or seasonally monitored and water quality advisories—such as for algal blooms—or poor weather can lead to temporary closures. Cold water, sudden drop-offs, and currents near inlets or the dam also present hazards, so swimming is typically allowed but undertaken at one’s own risk and in accordance with posted guidance from park authorities.