Cottonwood Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Cottonwood Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Cottonwood Lake today is 18.9°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 |
|---|---|---|---|
| SEP 14 | 21.1°C | 21.2°C | |
| SEP 15 | 20.4°C | 21.2°C | |
| SEP 16 | 20.2°C | 21.2°C | |
| SEP 17 | 19.9°C | 21.2°C | |
| SEP 18 | 19.1°C | 21.2°C | |
| SEP 19 | 19.7°C | 21.2°C | |
| SEP 20 | 19.1°C | 21.2°C | |
| SEP 21 | 18.9°C | 21.2°C | |
| SEP 22 | 21.2°C | 19.0°C | |
| SEP 23 | 21.2°C | 19.1°C | |
| SEP 24 | 21.2°C | 19.2°C | |
| SEP 25 | 21.2°C | 19.4°C | |
| SEP 26 | 21.2°C | 19.5°C | |
| SEP 27 | 21.2°C | 19.6°C | |
| SEP 28 | 21.2°C | 19.7°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 | 1°C | 7°C | 12°C |
| February | 1°C | 8°C | 15°C |
| March | 1°C | 9°C | 17°C |
| April | 3°C | 12°C | 20°C |
| May | 9°C | 16°C | 23°C |
| June | 16°C | 19°C | 23°C |
| July | 17°C | 23°C | 29°C |
| August | 21°C | 25°C | 28°C |
| September | 17°C | 21°C | 26°C |
| October | 5°C | 12°C | 18°C |
| November | 4°C | 7°C | 10°C |
| December | 2°C | 7°C | 11°C |
Cottonwood Lake: Water Temperature by Location
Cottonwood Lake: Weather Forecast
September 22
September 23
September 24
September 25
Location & Local Information
Cottonwood Lake, like many shallow prairie lakes in South Dakota, experiences pronounced seasonal swings in surface water temperature. In spring the lake often runs cold, commonly between about 40–60°F (4–16°C) as air temperatures recover. Summer brings the warmest conditions with typical surface readings around 68–78°F (20–26°C) and on hot spells the surface can climb into the low 80s°F (27–29°C). During autumn the water cools back toward roughly 50–65°F (10–18°C) before ice formation in winter, when surface temperatures sit at or just above freezing (around 32–34°F / 0–1°C) and the lake may be ice-covered for months. Deeper water stays more stable and colder than the surface throughout the year.
Swimming at Cottonwood Lake is generally allowed during the open season and is a common recreational use, especially when local parks or beaches post that the area is open. Whether swimming is advisable depends on current conditions and local advisories: authorities may close or discourage swimming because of harmful algal blooms, elevated bacterial counts, hazardous weather, thin ice, or other safety concerns. Visitors should follow posted signs, check any municipal or county advisories before entering the water, and be mindful that shallow prairie lakes can have weeds, poor visibility, and rapid temperature changes that affect safety.