Lake Madison — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Madison, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Madison today is 21.9°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 3 | 19.2°C | 19.0°C | |
| JUN 4 | 19.1°C | 19.0°C | |
| JUN 5 | 20.4°C | 19.0°C | |
| JUN 6 | 20.9°C | 19.0°C | |
| JUN 7 | 21.5°C | 19.0°C | |
| JUN 8 | 21.5°C | 19.0°C | |
| JUN 10 | 21.9°C | 19.0°C | |
| JUN 11 | 19.0°C | 21.8°C | |
| JUN 12 | 19.0°C | 21.6°C | |
| JUN 13 | 19.0°C | 21.5°C | |
| JUN 14 | 19.0°C | 21.3°C | |
| JUN 15 | 19.0°C | 21.2°C | |
| JUN 16 | 19.0°C | 21.0°C | |
| JUN 17 | 19.0°C | 20.9°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 | 6°C | 12°C |
| February | 0°C | 8°C | 15°C |
| March | 0°C | 9°C | 17°C |
| April | 4°C | 12°C | 20°C |
| May | 9°C | 15°C | 22°C |
| June | 16°C | 19°C | 22°C |
| July | 17°C | 21°C | 24°C |
| August | 21°C | 25°C | 28°C |
| September | 17°C | 20°C | 22°C |
| October | 5°C | 12°C | 19°C |
| November | 4°C | 8°C | 11°C |
| December | 0°C | 6°C | 11°C |
Lake Madison: Water Temperature by Location
Lake Madison: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Lake Madison is a shallow glacially influenced lake in eastern South Dakota whose surface temperatures change markedly through the year. In winter the lake commonly freezes and surface water sits around the freezing point near 32°F (0°C). During spring, warming waters typically range from roughly 40–60°F (4–16°C) as ice melts and runoff cools the lake. In summer the surface warms most days, often reaching about 68–80°F (20–27°C) in July and August on sunny afternoons, though deeper or wind-driven areas may remain several degrees cooler. By early fall temperatures generally fall back into the 50–68°F (10–20°C) range before ice returns.
Swimming is permitted at public access points and designated beaches around Lake Madison during the warmer months, and many people swim there when surface temperatures are comfortable. Local authorities, however, can close or advise against swimming for safety or health reasons: ice cover in winter makes swimming impossible, and in summer periodic water-quality issues such as elevated bacteria or blue‑green algae blooms may prompt advisories. Users should follow posted notices, avoid swimming in cold shoulder seasons when hypothermia risk is higher, and heed lifeguards or county guidance when present.