Lake Poygan — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Poygan, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Poygan today is 19.9°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 |
|---|---|---|---|
| JUN 3 | 19.8°C | 17.5°C | |
| JUN 4 | 19.8°C | 17.5°C | |
| JUN 5 | 20.0°C | 17.5°C | |
| JUN 6 | 19.9°C | 17.5°C | |
| JUN 7 | 20.2°C | 17.5°C | |
| JUN 8 | 20.2°C | 17.5°C | |
| JUN 11 | 17.5°C | 19.8°C | |
| JUN 12 | 17.5°C | 19.7°C | |
| JUN 13 | 17.5°C | 19.5°C | |
| JUN 14 | 17.5°C | 19.4°C | |
| JUN 15 | 17.5°C | 19.3°C | |
| JUN 16 | 17.5°C | 19.2°C | |
| JUN 17 | 17.5°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 | 2°C | 4°C |
| February | 0°C | 4°C | 6°C |
| March | 1°C | 5°C | 8°C |
| April | 2°C | 7°C | 12°C |
| May | 7°C | 13°C | 20°C |
| June | 14°C | 18°C | 21°C |
| July | 19°C | 24°C | 29°C |
| August | 20°C | 24°C | 27°C |
| September | 17°C | 20°C | 22°C |
| October | 13°C | 16°C | 19°C |
| November | 3°C | 9°C | 15°C |
| December | 0°C | 3°C | 6°C |
Lake Poygan: Water Temperature by Location
Lake Poygan: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Lake Poygan, part of Wisconsin’s Winnebago pool, experiences notable seasonal variability in surface water temperature because it is relatively shallow and influenced by river flow and weather. In winter the surface typically hovers around freezing, about 32–40°F (0–4°C) when ice is present or just melting. Spring brings a steady rise, with temperatures often in the 40–60°F range (4–16°C) as the lake thaws and warms through April and May. Peak summer conditions usually occur in July and August, when surface water commonly reaches roughly 68–80°F (20–27°C), though shallow bays can heat even a few degrees higher on hot, calm days. In early fall the lake cools back into the 50–70°F band (10–21°C) before returning toward winter values.
Swimming in Lake Poygan is generally allowed because it is public freshwater, and many people recreate there during warm months. However, conditions that affect safety and comfort should guide decisions: summer temperatures are often comfortable for swimming, but extensive aquatic vegetation, soft or muddy bottoms, boat traffic, and occasional harmful algal blooms or bacterial advisories can make particular spots unsuitable. Because of these localized and seasonal hazards, swimmers are advised to use designated access areas, be mindful of water quality advisories, and exercise caution around boats and shallow, vegetated zones.