Fish Lake Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Fish Lake Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Fish Lake Reservoir 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 | 19.4°C | 18.1°C | |
| SEP 15 | 18.2°C | 18.1°C | |
| SEP 16 | 18.0°C | 18.1°C | |
| SEP 17 | 17.1°C | 18.1°C | |
| SEP 18 | 17.0°C | 18.1°C | |
| SEP 19 | 17.0°C | 18.1°C | |
| SEP 20 | 16.4°C | 18.1°C | |
| SEP 22 | 18.1°C | 17.4°C | |
| SEP 23 | 18.1°C | 17.5°C | |
| SEP 24 | 18.1°C | 17.5°C | |
| SEP 25 | 18.1°C | 17.5°C | |
| SEP 26 | 18.1°C | 17.6°C | |
| SEP 27 | 18.1°C | 17.6°C | |
| SEP 28 | 18.1°C | 17.6°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 | 1°C | 3°C |
| February | 0°C | 1°C | 3°C |
| March | 0°C | 1°C | 3°C |
| April | 1°C | 5°C | 10°C |
| May | 3°C | 10°C | 18°C |
| June | 15°C | 18°C | 21°C |
| July | 18°C | 23°C | 27°C |
| August | 18°C | 24°C | 30°C |
| September | 14°C | 18°C | 23°C |
| October | 9°C | 13°C | 17°C |
| November | 1°C | 7°C | 11°C |
| December | 0°C | 2°C | 3°C |
Fish Lake Reservoir: Water Temperature by Location
Fish Lake Reservoir: Weather Forecast
September 22
September 23
September 24
September 25
Location & Local Information
Fish Lake Reservoir in Minnesota experiences marked seasonal shifts in water temperature. In winter the surface and near-shore water commonly sits at or just above freezing, around 32°F (0°C), with ice cover typical. During spring it slowly warms into the 40s–60s°F range (about 4–15°C) as snowmelt and air temperatures rise. Summer surface temperatures are most comfortable for swimmers, often reaching the low 70s to around 80°F (21–27°C) on warm afternoons and occasionally a few degrees higher in shallow bays. In autumn the lake cools again, with surface readings typically falling into the 50s–60s°F (10–18°C) before winter sets in. Actual temperatures vary by year, weather, depth and location within the reservoir.
Swimming at Fish Lake Reservoir is generally possible where public access and designated recreation areas exist, because reservoirs in Minnesota are commonly managed to support multiple recreational uses including bathing. Whether you should swim depends on conditions: summer surface temperatures in the 70s°F (20s°C) are comfortable, whereas cooler spring and fall waters are bracing and winter conditions are unsafe without ice‑specific precautions. Local rules, water quality advisories, boat traffic, currents, and submerged hazards can restrict or make swimming unsafe, so checking signage and current conditions is advised before entering the water.