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 24.8°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 75°F (23°C) to 79°F (26°C). This is a very comfortable temperature for swimming, and many people can enjoy prolonged stays in the water without feeling cold. The water is pleasantly warm, making it ideal for relaxation and water sports. This temperature range is particularly popular among tourists, as it combines comfort and safety for health. 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 |
|---|---|---|---|
| AUG 4 | 25.8°C | 24.5°C | |
| AUG 5 | 25.6°C | 24.5°C | |
| AUG 6 | 25.0°C | 24.5°C | |
| AUG 7 | 24.6°C | 24.5°C | |
| AUG 8 | 24.7°C | 24.5°C | |
| AUG 9 | 24.7°C | 24.5°C | |
| AUG 10 | 24.8°C | 24.5°C | |
| AUG 11 | 24.8°C | 24.5°C | |
| AUG 12 | 24.5°C | 24.8°C | |
| AUG 13 | 24.5°C | 24.8°C | |
| AUG 14 | 24.5°C | 24.8°C | |
| AUG 15 | 24.5°C | 24.7°C | |
| AUG 16 | 24.5°C | 24.7°C | |
| AUG 17 | 24.5°C | 24.7°C | |
| AUG 18 | 24.5°C | 24.7°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 | 20°C | 25°C |
| July | 17°C | 23°C | 29°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
August 12
August 13
August 14
August 15
August 16
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.