Angostura Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Angostura Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Angostura Reservoir today is 21.1°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 2 | 21.3°C | 19.6°C | |
| JUN 3 | 21.3°C | 19.6°C | |
| JUN 4 | 21.3°C | 19.6°C | |
| JUN 5 | 21.5°C | 19.6°C | |
| JUN 6 | 21.7°C | 19.6°C | |
| JUN 7 | 22.1°C | 19.6°C | |
| JUN 8 | 21.8°C | 19.6°C | |
| JUN 10 | 19.6°C | 21.0°C | |
| JUN 11 | 19.6°C | 21.0°C | |
| JUN 12 | 19.6°C | 20.9°C | |
| JUN 13 | 19.6°C | 20.8°C | |
| JUN 14 | 19.6°C | 20.7°C | |
| JUN 15 | 19.6°C | 20.7°C | |
| JUN 16 | 19.6°C | 20.6°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 | 3°C | 6°C |
| February | 0°C | 3°C | 6°C |
| March | 0°C | 4°C | 9°C |
| April | 4°C | 9°C | 15°C |
| May | 9°C | 16°C | 23°C |
| June | 17°C | 20°C | 23°C |
| July | 21°C | 24°C | 27°C |
| August | 22°C | 25°C | 28°C |
| September | 16°C | 19°C | 22°C |
| October | 9°C | 14°C | 18°C |
| November | 5°C | 8°C | 10°C |
| December | 0°C | 3°C | 7°C |
Angostura Reservoir: Water Temperature by Location
Angostura Reservoir: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Angostura Reservoir, often called Lake Angostura near Hot Springs, South Dakota, experiences marked seasonal swings in surface water temperature. In spring (April–May) surface temperatures typically run about 40–60°F (4–16°C) as the lake warms after ice-out. Summer temperatures (June–August) are the warmest, commonly ranging from roughly 70–80°F (21–27°C) and occasionally reaching the low 80s°F (27–28°C) during heat waves. Early fall (September–October) sees cooling back into the 40–60°F range (4–16°C) while winter months are near freezing, with water at or just above 32°F (0°C) beneath ice cover.
Swimming is generally allowed at Angostura in designated beach areas within the state recreation area and at resort beaches during the warm season, primarily late spring through early fall when surface temperatures are comfortable. Authorities may post restrictions or advisories for public safety — for example when cyanobacterial (blue‑green algae) blooms occur, during high winds or unsafe conditions, or when ice renders access hazardous. Even in summer, swimmers should be aware of sudden temperature changes and cold‑water shock risk outside peak warm weeks, and follow posted rules and local guidance for safe swimming.