Lake Winnebago — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Winnebago, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Winnebago 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 | 20.2°C | 17.8°C | |
| SEP 15 | 20.4°C | 17.8°C | |
| SEP 16 | 20.1°C | 17.8°C | |
| SEP 17 | 20.0°C | 17.8°C | |
| SEP 18 | 19.5°C | 17.8°C | |
| SEP 19 | 19.9°C | 17.8°C | |
| SEP 20 | 19.3°C | 17.8°C | |
| SEP 21 | 19.3°C | 17.8°C | |
| SEP 22 | 17.8°C | 19.2°C | |
| SEP 23 | 17.8°C | 19.2°C | |
| SEP 24 | 17.8°C | 19.1°C | |
| SEP 25 | 17.8°C | 19.0°C | |
| SEP 26 | 17.8°C | 18.9°C | |
| SEP 27 | 17.8°C | 18.9°C | |
| SEP 28 | 17.8°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 | 1°C | 4°C | 7°C |
| February | 0°C | 5°C | 8°C |
| March | 0°C | 3°C | 5°C |
| April | 2°C | 7°C | 12°C |
| May | 8°C | 16°C | 23°C |
| June | 17°C | 20°C | 23°C |
| July | 20°C | 24°C | 29°C |
| August | 21°C | 24°C | 27°C |
| September | 12°C | 18°C | 24°C |
| October | 13°C | 16°C | 19°C |
| November | 0°C | 5°C | 9°C |
| December | 0°C | 2°C | 5°C |
Lake Winnebago: Water Temperature by Location
Lake Winnebago: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Lake Winnebago, a large, relatively shallow lake in eastern Wisconsin, experiences marked seasonal shifts in water temperature. In winter the surface commonly approaches freezing, around 32°F (0°C) under ice cover. Spring brings a gradual rise, with temperatures typically in the 40s to low 60s °F (about 4–16°C) as the lake stratifies. Summer is the warmest period, when surface water often reaches the upper 60s to mid-80s °F (about 20–29°C) depending on sunlight and wind; frequent summer readings are in the 70s °F (21–27°C). By fall the lake cools again into the 50s and 40s °F (10–7°C) before ice returns. Because Winnebago is shallow and broad, surface temperatures can warm relatively quickly but also respond to wind and incoming tributary flows, producing variability across the lake.
Swimming at Lake Winnebago is permitted at many public beaches and along shorelines, and recreational swimming is common in warm months. However, use is subject to local health and safety considerations: authorities may post advisories after heavy rains due to bacterial runoff, or during harmful algal blooms (cyanobacteria) that can make contact unsafe. Other practical concerns include boat traffic, submerged vegetation and variable visibility, and the risk of cold shock outside the warmest months. Swimmers should heed posted signs and local guidance for current water quality and safety conditions.