Oconomowoc Lake 87 — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Oconomowoc Lake 87, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Oconomowoc Lake 87 today is 19.6°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 | 19.8°C | 21.0°C | |
| SEP 15 | 19.9°C | 21.0°C | |
| SEP 16 | 19.5°C | 21.0°C | |
| SEP 17 | 19.8°C | 21.0°C | |
| SEP 18 | 19.4°C | 21.0°C | |
| SEP 19 | 19.4°C | 21.0°C | |
| SEP 20 | 19.1°C | 21.0°C | |
| SEP 22 | 21.0°C | 19.7°C | |
| SEP 23 | 21.0°C | 19.7°C | |
| SEP 24 | 21.0°C | 19.8°C | |
| SEP 25 | 21.0°C | 19.9°C | |
| SEP 26 | 21.0°C | 20.0°C | |
| SEP 27 | 21.0°C | 20.0°C | |
| SEP 28 | 21.0°C | 20.1°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 | 2°C | 4°C |
| February | 1°C | 4°C | 6°C |
| March | 1°C | 5°C | 8°C |
| April | 5°C | 9°C | 13°C |
| May | 7°C | 13°C | 19°C |
| June | 16°C | 19°C | 23°C |
| July | 20°C | 25°C | 30°C |
| August | 22°C | 25°C | 27°C |
| September | 18°C | 21°C | 24°C |
| October | 13°C | 17°C | 20°C |
| November | 3°C | 9°C | 15°C |
| December | 0°C | 3°C | 6°C |
Oconomowoc Lake 87: Water Temperature by Location
Oconomowoc Lake 87: Weather Forecast
September 21
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Oconomowoc Lake in Wisconsin follows the seasonal patterns typical of midwestern glacial lakes. Surface water temperatures in winter often hover near freezing, around 32–40°F (0–4°C), and the lake can develop ice cover. Spring brings a steady warming to roughly 40–60°F (4–16°C) as ice melts and evenings warm. Summer is when surface temperatures peak, commonly ranging from about 68–82°F (20–28°C) on warm, sunny days; shallow bays can be a few degrees warmer while deeper water remains noticeably cooler. In fall the surface cools again to roughly 45–65°F (7–18°C) as the lake destratifies and loses heat to shortening days and cooler air.
Swimming is generally allowed in Oconomowoc Lake at public access points and private beaches, subject to local ordinances and property restrictions. Whether it is advisable to swim depends on conditions: many people find water above about 75°F (24°C) comfortable, whereas temperatures below ~70°F (21°C) can feel cold and increase risk of cold-water shock. Seasonal hazards such as algal (cyanobacteria) blooms, bacterial contamination after heavy rains, wind-driven waves, and boat traffic can lead to temporary advisories or closures, so checking current local health and park notices before entering the water is recommended.