Upper Prior Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Upper Prior Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Upper Prior Lake today is 18.6°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 | 20.0°C | 21.3°C | |
| SEP 15 | 19.9°C | 21.3°C | |
| SEP 16 | 18.9°C | 21.3°C | |
| SEP 17 | 17.8°C | 21.3°C | |
| SEP 18 | 17.9°C | 21.3°C | |
| SEP 19 | 17.9°C | 21.3°C | |
| SEP 20 | 18.2°C | 21.3°C | |
| SEP 21 | 18.6°C | 21.3°C | |
| SEP 22 | 21.3°C | 18.7°C | |
| SEP 23 | 21.3°C | 18.9°C | |
| SEP 24 | 21.3°C | 19.0°C | |
| SEP 25 | 21.3°C | 19.1°C | |
| SEP 26 | 21.3°C | 19.3°C | |
| SEP 27 | 21.3°C | 19.4°C | |
| SEP 28 | 21.3°C | 19.5°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 | 7°C |
| February | 0°C | 3°C | 7°C |
| March | 0°C | 4°C | 9°C |
| April | 4°C | 9°C | 15°C |
| May | 11°C | 16°C | 22°C |
| June | 17°C | 22°C | 27°C |
| July | 22°C | 25°C | 28°C |
| August | 20°C | 24°C | 28°C |
| September | 18°C | 21°C | 25°C |
| October | 6°C | 13°C | 19°C |
| November | 3°C | 7°C | 11°C |
| December | 1°C | 5°C | 8°C |
Upper Prior Lake: Water Temperature by Location
Upper Prior Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Upper Prior Lake follows the seasonal pattern typical of southern Minnesota lakes. In winter the surface is at or near freezing, often iced over, with surface temperatures around 32°F (0°C) or slightly lower under ice cover. As spring warms the lake moves through the 34–55°F (1–13°C) range while ice-out and turnover occur. Summer brings the warmest surface conditions, often between about 65–80°F (18–27°C) during June through August, with peak afternoons occasionally a few degrees warmer. By fall the water cools again, generally settling into roughly 45–60°F (7–16°C) before refreezing as winter approaches.
Swimming in Upper Prior Lake is commonly practiced during the open-water season and is generally permitted, particularly in public or designated recreation areas, because the lake is used for multiple recreational purposes. Comfort and safety vary with temperature: waters in the 70s°F (around 21–27°C) are pleasant for most swimmers, while cooler spring or late‑season temperatures can feel brisk and increase the risk of cold shock. Local authorities may temporarily restrict swimming for safety or health reasons such as unsafe ice conditions, strong storms, or water quality issues like algal blooms, so following posted guidance and advisories is important before entering the water.