Lake Altoona — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Altoona, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Altoona today is 19.3°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 65°F (18°C) to 68°F (20°C). This is already quite warm water, which is ideal for most people. Swimming becomes comfortable, and prolonged stays in the water do not cause discomfort. This temperature is perfect for family trips and for those who prefer warmer water. It is also comfortable for water sports such as surfing or swimming. 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 14 | 21.1°C | 18.8°C | |
| SEP 15 | 19.8°C | 18.8°C | |
| SEP 16 | 20.0°C | 18.8°C | |
| SEP 17 | 20.3°C | 18.8°C | |
| SEP 18 | 19.3°C | 18.8°C | |
| SEP 19 | 19.8°C | 18.8°C | |
| SEP 20 | 19.8°C | 18.8°C | |
| SEP 21 | 19.3°C | 18.8°C | |
| SEP 22 | 18.8°C | 19.3°C | |
| SEP 23 | 18.8°C | 19.3°C | |
| SEP 24 | 18.8°C | 19.2°C | |
| SEP 25 | 18.8°C | 19.2°C | |
| SEP 26 | 18.8°C | 19.2°C | |
| SEP 27 | 18.8°C | 19.2°C | |
| SEP 28 | 18.8°C | 19.1°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 | 2°C | 5°C |
| April | 1°C | 8°C | 16°C |
| May | 8°C | 15°C | 22°C |
| June | 15°C | 19°C | 23°C |
| July | 20°C | 24°C | 28°C |
| August | 20°C | 25°C | 30°C |
| September | 14°C | 19°C | 24°C |
| October | 9°C | 14°C | 18°C |
| November | 2°C | 7°C | 12°C |
| December | 0°C | 1°C | 3°C |
Lake Altoona: Water Temperature by Location
Lake Altoona: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Lake Altoona, a reservoir near Eau Claire, Wisconsin, experiences pronounced seasonal changes in water temperature. In spring the surface typically ranges from about 40–60°F (4–16°C) as runoff and cooler air moderate the lake. By summer, surface temperatures commonly climb into the mid‑70s up to around 80°F (21–27°C) on warm afternoons, especially in shallower bays where sunlight warms the water fastest. Early fall sees a gradual cooling to roughly 50–65°F (10–18°C) before the lake moves toward winter stratification and, ultimately, ice cover. In winter the water near the surface approaches freezing, around 32°F (0°C), with complete ice cover at times until thaw.
Swimming is generally allowed at Lake Altoona, particularly at the designated beach areas in Lake Altoona County Park, where public access and seasonal amenities make recreational swimming practicable. Authorities monitor water quality and may post advisories for bacterial contamination or harmful algal blooms, so conditions sometimes restrict swimming for health reasons. Even when open, swimmers should consider temperature and safety: colder water increases hypothermia risk and reduces swimming endurance, while summer warmth can bring algae or increased recreational traffic. Lifeguards may be present seasonally at park beaches, but shoreline swimming outside marked areas carries additional risks.