Flathead River — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in the Flathead River, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in the Flathead River today is 19.9°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 |
|---|---|---|---|
| AUG 24 | 22.8°C | 20.7°C | |
| AUG 25 | 21.5°C | 20.7°C | |
| AUG 26 | 21.3°C | 20.7°C | |
| AUG 27 | 21.2°C | 20.7°C | |
| AUG 28 | 21.0°C | 20.7°C | |
| AUG 29 | 20.9°C | 20.7°C | |
| AUG 30 | 20.9°C | 20.7°C | |
| AUG 31 | 19.8°C | 20.7°C | |
| SEP 1 | 15.5°C | 19.7°C | |
| SEP 2 | 15.5°C | 19.5°C | |
| SEP 3 | 15.5°C | 19.2°C | |
| SEP 4 | 15.5°C | 19.0°C | |
| SEP 5 | 15.5°C | 18.8°C | |
| SEP 6 | 15.5°C | 18.6°C | |
| SEP 7 | 15.5°C | 18.4°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 | 1°C | 5°C | 9°C |
| February | 1°C | 5°C | 9°C |
| March | 0°C | 6°C | 11°C |
| April | 1°C | 9°C | 16°C |
| May | 4°C | 13°C | 21°C |
| June | 10°C | 16°C | 22°C |
| July | 15°C | 20°C | 24°C |
| August | 17°C | 21°C | 25°C |
| September | 11°C | 16°C | 20°C |
| October | 8°C | 13°C | 17°C |
| November | 3°C | 8°C | 16°C |
| December | 3°C | 5°C | 8°C |
Flathead River: Water Temperature by Location
Flathead River: Weather Forecast
September 1
September 2
September 3
September 4
September 5
Location & Local Information
Source Confluence of North Fork and Middle Fork Flathead River
• location Rocky Mountains
• elevation 3,120 ft (950 m)
Mouth Clark Fork
• location Montana
• elevation 2,484 ft (757 m)
Length 158 mi (254 km)
The Flathead River, located in northwestern Montana, is a pristine waterway known for its clear waters and stunning surroundings, including Glacier National Park. Its water temperature is significantly influenced by snowmelt from nearby mountains, keeping the river cold for much of the year. During spring and early summer, temperatures often hover between 40°F and 50°F (4°C–10°C), making the water brisk and refreshing. By mid to late summer, in slower sections or areas exposed to the sun, water temperatures can reach up to 60°F–70°F (15°C–21°C), providing more comfortable conditions for recreational activities.
Swimming in the Flathead River is possible during the warmer months, especially in calmer areas like river bends or designated swimming spots near campgrounds and parks. However, the river’s strong currents and cold water make it more suited for activities like floating, kayaking, and paddleboarding. For those looking to swim, it’s best to stick to shallow, still sections and always exercise caution due to the river’s varying depths and flow rates. The Flathead River offers a unique opportunity to enjoy Montana’s natural beauty while cooling off in its refreshing waters.