Lake Herman — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Herman, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Herman today is 17.4°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people. 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 | 20.3°C | 21.1°C | |
| SEP 15 | 18.9°C | 21.1°C | |
| SEP 16 | 18.6°C | 21.1°C | |
| SEP 17 | 18.4°C | 21.1°C | |
| SEP 18 | 17.4°C | 21.1°C | |
| SEP 19 | 17.6°C | 21.1°C | |
| SEP 20 | 17.7°C | 21.1°C | |
| SEP 21 | 17.4°C | 21.1°C | |
| SEP 22 | 21.1°C | 17.6°C | |
| SEP 23 | 21.1°C | 17.8°C | |
| SEP 24 | 21.1°C | 18.0°C | |
| SEP 25 | 21.1°C | 18.1°C | |
| SEP 26 | 21.1°C | 18.3°C | |
| SEP 27 | 21.1°C | 18.5°C | |
| SEP 28 | 21.1°C | 18.7°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 | 3°C | 12°C | 20°C |
| May | 8°C | 15°C | 22°C |
| June | 15°C | 20°C | 25°C |
| July | 17°C | 22°C | 28°C |
| August | 20°C | 24°C | 28°C |
| September | 17°C | 21°C | 26°C |
| October | 5°C | 12°C | 19°C |
| November | 3°C | 7°C | 10°C |
| December | 0°C | 4°C | 8°C |
Lake Herman: Water Temperature by Location
Lake Herman: Weather Forecast
September 22
September 23
September 24
September 25
Location & Local Information
Lake Herman’s surface water temperatures follow the typical seasonal cycle for prairie lakes in South Dakota. In spring the lake warms from near-freezing as ice breaks up to roughly the mid-50s–low 60s °F (about 12–16 °C) by late spring. Summer surface temperatures commonly range from the mid-60s to upper-70s °F (around 18–26 °C), and on hot, calm stretches can reach the low-to-mid 80s °F (28–30 °C). As air temperatures fall in autumn the water cools back to roughly the 40s–60s °F (5–15 °C). In winter the lake typically forms ice and surface water is at or near freezing (32 °F, 0 °C), with liquid water under the ice staying just above freezing.
Swimming is generally possible and is most practical during the warm summer months when surface temperatures are comfortable. Public access areas and beaches are used for bathing, but swimmers should observe posted rules, watch for water-quality advisories such as algae blooms, and be aware that organized lifeguards may not be present. Cold water in spring and fall increases the risk of cold-water shock, and winter swimming is unsafe because of ice and near-freezing temperatures. Always check local notices before entering the water.