Sweeney Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Sweeney Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Sweeney Lake today is 19.1°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 | 22.6°C | 21.5°C | |
| SEP 15 | 22.2°C | 21.5°C | |
| SEP 16 | 21.3°C | 21.5°C | |
| SEP 17 | 19.3°C | 21.5°C | |
| SEP 18 | 19.4°C | 21.5°C | |
| SEP 19 | 19.7°C | 21.5°C | |
| SEP 20 | 20.1°C | 21.5°C | |
| SEP 21 | 19.1°C | 21.5°C | |
| SEP 22 | 21.5°C | 19.2°C | |
| SEP 23 | 21.5°C | 19.3°C | |
| SEP 24 | 21.5°C | 19.5°C | |
| SEP 25 | 21.5°C | 19.6°C | |
| SEP 26 | 21.5°C | 19.7°C | |
| SEP 27 | 21.5°C | 19.8°C | |
| SEP 28 | 21.5°C | 19.9°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 | 4°C | 7°C |
| February | 0°C | 3°C | 6°C |
| March | 0°C | 3°C | 7°C |
| April | 4°C | 9°C | 15°C |
| May | 11°C | 17°C | 23°C |
| June | 19°C | 24°C | 27°C |
| July | 22°C | 25°C | 29°C |
| August | 22°C | 25°C | 28°C |
| September | 18°C | 22°C | 25°C |
| October | 6°C | 14°C | 21°C |
| November | 3°C | 8°C | 12°C |
| December | 1°C | 4°C | 7°C |
Sweeney Lake: Water Temperature by Location
Sweeney Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Sweeney Lake in Minnesota follows the familiar seasonal rhythm of midwestern glacial lakes when it comes to water temperature. During winter months the surface is typically ice-covered and water temperatures hover around freezing, about 32°F (0°C) near the ice interface. In spring the lake gradually warms, often ranging from roughly 40–55°F (4–13°C) as snowmelt and cool rains moderate conditions. Peak summer temperatures are usually the most comfortable for swimming, commonly between about 68–78°F (20–26°C) and occasionally reaching near 80°F (27°C) in extended heat spells. By autumn the surface cools again, with temperatures generally falling into the 50–60°F (10–16°C) window before ice return.
Swimming is generally possible at Sweeney Lake during the open-water season—late spring through early fall—provided the lake is ice free and local authorities have not posted advisories. Managers may restrict or discourage swimming for reasons such as elevated bacteria counts, harmful algal blooms, or hazardous conditions like strong currents or sudden drops; ice makes winter swimming unsafe without specialized precautions. Visitors are advised to observe posted signs and local guidance about water quality and safety, because allowable swimming depends on both seasonal temperatures and real-time assessments of hazards and water clarity.