Thunder Bay — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Thunder Bay, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Thunder Bay today is 18.3°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 6 | 19.0°C | 16.6°C | |
| SEP 7 | 18.8°C | 16.6°C | |
| SEP 8 | 18.6°C | 16.6°C | |
| SEP 9 | 18.5°C | 16.6°C | |
| SEP 10 | 18.3°C | 16.6°C | |
| SEP 12 | 17.8°C | 16.6°C | |
| SEP 13 | 18.0°C | 16.6°C | |
| SEP 14 | 16.6°C | 18.2°C | |
| SEP 15 | 16.6°C | 18.1°C | |
| SEP 16 | 16.6°C | 18.0°C | |
| SEP 17 | 16.6°C | 18.0°C | |
| SEP 18 | 16.6°C | 17.9°C | |
| SEP 19 | 16.6°C | 17.8°C | |
| SEP 20 | 16.6°C | 17.7°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 | 4°C |
| February | -1°C | 1°C | 4°C |
| March | -1°C | 1°C | 4°C |
| April | 0°C | 5°C | 10°C |
| May | 1°C | 7°C | 14°C |
| June | 5°C | 13°C | 21°C |
| July | 12°C | 18°C | 25°C |
| August | 14°C | 19°C | 25°C |
| September | 11°C | 17°C | 23°C |
| October | 6°C | 12°C | 18°C |
| November | 2°C | 8°C | 12°C |
| December | 0°C | 3°C | 5°C |
Thunder Bay: Weather Forecast
September 14
September 15
September 16
September 17
September 18
Location & Local Information
Thunder Bay, located on the northwestern shore of Lake Superior, offers a beautiful but much colder swimming experience compared to other lakes in Ontario. The water temperature in Lake Superior near Thunder Bay can be quite chilly, even during the summer. During the warmer months, the water typically ranges from 50°F to 60°F (10°C to 15°C), which may feel brisk to swimmers. While it is swimmable, it can be a shock to the system for those who are not accustomed to colder waters. Many locals enjoy a quick dip, but the lake's cold temperatures may limit extended swimming sessions for most.
Despite the chilly water, Thunder Bay is known for its stunning beaches, such as the popular Sandy Beach and Boulevard Lake, which draw visitors for both relaxation and water activities. Although swimming is less common due to the cold temperatures, other activities such as kayaking, paddleboarding, and boating are quite popular. Lake Superior’s size and depth contribute to its colder water year-round, which is why it's essential to be prepared for lower temperatures if planning to swim or enjoy water sports.
In the winter months, the water temperature in Lake Superior around Thunder Bay drops further, often reaching around 32°F (0°C), freezing over in some areas. Swimming during this time is not recommended. However, during the summer, those who brave the cold waters are often rewarded with peaceful, scenic surroundings and the opportunity to cool off in one of the largest and most beautiful freshwater lakes in the world.