South Arm Knife Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in South Arm Knife Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in South Arm Knife Lake today is 20.4°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 |
|---|---|---|---|
| AUG 4 | 22.9°C | 23.5°C | |
| AUG 5 | 22.9°C | 23.5°C | |
| AUG 6 | 22.4°C | 23.5°C | |
| AUG 7 | 22.4°C | 23.5°C | |
| AUG 8 | 22.4°C | 23.5°C | |
| AUG 9 | 22.4°C | 23.5°C | |
| AUG 10 | 22.4°C | 23.5°C | |
| AUG 11 | 20.3°C | 23.5°C | |
| AUG 12 | 23.5°C | 20.6°C | |
| AUG 13 | 23.5°C | 20.7°C | |
| AUG 14 | 23.5°C | 20.9°C | |
| AUG 15 | 23.5°C | 21.0°C | |
| AUG 16 | 23.5°C | 21.2°C | |
| AUG 17 | 23.5°C | 21.3°C | |
| AUG 18 | 23.5°C | 21.5°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 | 2°C | 5°C |
| February | 0°C | 2°C | 4°C |
| March | 0°C | 1°C | 3°C |
| April | 1°C | 4°C | 6°C |
| May | 4°C | 10°C | 16°C |
| June | 11°C | 16°C | 21°C |
| July | 18°C | 23°C | 27°C |
| August | 17°C | 24°C | 30°C |
| September | 14°C | 16°C | 19°C |
| October | 9°C | 13°C | 16°C |
| November | 2°C | 7°C | 11°C |
| December | 0°C | 3°C | 6°C |
South Arm Knife Lake: Water Temperature by Location
South Arm Knife Lake: Weather Forecast
August 12
August 13
August 14
August 15
August 16
Location & Local Information
The South Arm of Knife Lake in northeastern Minnesota typically follows the seasonal temperature patterns of other shallow northern lakes. In winter the surface settles at or just below freezing (about 32°F/0°C) where ice forms, while spring thaw brings cold, often 35–50°F (2–10°C) water. By midsummer the surface in sheltered bays and shoals commonly warms to roughly 60–75°F (15–24°C), and on unusually warm, calm spells can briefly reach the upper 70s°F (around 25–26°C). Deeper water remains much colder through the summer because of thermal stratification, so temperatures drop rapidly below the thermocline. In autumn the lake cools back through the 40s–60s°F range (5–16°C) before refreezing.
Swimming is generally possible and is a common recreational use during the warm months when surface temperatures are comfortable; there are no inherent legal prohibitions on swimming in a natural lake unless specific local rules apply. However, access depends on shoreline ownership and any posted restrictions, and safety considerations are important: cold water in spring and late fall can cause cold-shock responses, deeper water stays chilly, and there may be occasional water-quality advisories for algae or bacteria. Swimmers should use caution, avoid going alone, wear a life jacket when appropriate, and check local conditions before entering the water.