Rainy Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Rainy Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Rainy Lake today is 23°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 | 23.7°C | 23.5°C | |
| AUG 5 | 23.6°C | 23.5°C | |
| AUG 6 | 23.5°C | 23.5°C | |
| AUG 7 | 23.3°C | 23.5°C | |
| AUG 8 | 23.1°C | 23.5°C | |
| AUG 9 | 23.1°C | 23.5°C | |
| AUG 10 | 22.9°C | 23.5°C | |
| AUG 11 | 23.0°C | 23.5°C | |
| AUG 12 | 23.5°C | 23.0°C | |
| AUG 13 | 23.5°C | 23.1°C | |
| AUG 14 | 23.5°C | 23.1°C | |
| AUG 15 | 23.5°C | 23.1°C | |
| AUG 16 | 23.5°C | 23.1°C | |
| AUG 17 | 23.5°C | 23.2°C | |
| AUG 18 | 23.5°C | 23.2°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 | 6°C |
| February | 0°C | 3°C | 5°C |
| March | 0°C | 2°C | 5°C |
| April | 2°C | 6°C | 10°C |
| May | 2°C | 11°C | 19°C |
| June | 13°C | 20°C | 27°C |
| July | 15°C | 21°C | 27°C |
| August | 19°C | 24°C | 28°C |
| September | 16°C | 20°C | 23°C |
| October | 6°C | 12°C | 17°C |
| November | 3°C | 7°C | 11°C |
| December | 1°C | 4°C | 7°C |
Rainy Lake: Water Temperature by Location
Rainy Lake: Weather Forecast
August 12
August 13
August 14
August 15
August 16
Location & Local Information
Rainy Lake, forming part of the border between Minnesota and Ontario, is a large, deep, stratified lake that is subject to the extremes of the northern climate. In the cold winter months, the lake freezes completely, with water temperatures near freezing, typically ranging from 0∘C to 5∘C (32∘F to 41∘F). In the peak summer season, particularly late July and August, the surface water warms considerably, often reaching a comfortable range for swimming, generally peaking around 24∘C to 26∘C (75∘F to 79∘F) in the top layers.
Swimming is widely permitted and encouraged in Rainy Lake, especially in designated areas. Within the nearby Voyageurs National Park, the vast water area offers many swimming opportunities, with some islands featuring great sandy shore beaches. Furthermore, the City of International Falls maintains City Beach, which typically features a sandy shore and a roped-off swim area, confirming its status as a designated swimming site. However, the lake is deep and often unsupervised outside of the city beach, meaning all swimming is strictly at one's own risk, and caution is advised regarding boat traffic and the potential for cold deeper waters.