Bighorn Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Bighorn Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Bighorn Lake today is 18°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 | 20.9°C | 18.4°C | |
| SEP 15 | 20.7°C | 18.4°C | |
| SEP 16 | 20.8°C | 18.4°C | |
| SEP 17 | 20.3°C | 18.4°C | |
| SEP 18 | 19.2°C | 18.4°C | |
| SEP 19 | 18.6°C | 18.4°C | |
| SEP 20 | 19.0°C | 18.4°C | |
| SEP 22 | 18.4°C | 18.0°C | |
| SEP 23 | 18.4°C | 18.0°C | |
| SEP 24 | 18.4°C | 18.1°C | |
| SEP 25 | 18.4°C | 18.1°C | |
| SEP 26 | 18.4°C | 18.1°C | |
| SEP 27 | 18.4°C | 18.1°C | |
| SEP 28 | 18.4°C | 18.1°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 | 5°C |
| February | 1°C | 4°C | 7°C |
| March | 1°C | 5°C | 9°C |
| April | 0°C | 6°C | 13°C |
| May | 4°C | 11°C | 19°C |
| June | 11°C | 16°C | 20°C |
| July | 16°C | 22°C | 28°C |
| August | 18°C | 23°C | 28°C |
| September | 14°C | 18°C | 23°C |
| October | 7°C | 12°C | 17°C |
| November | 3°C | 6°C | 9°C |
| December | 2°C | 4°C | 7°C |
Bighorn Lake: Water Temperature by Location
Bighorn Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Bighorn Lake, the reservoir behind Yellowtail Dam that stretches from Montana into Wyoming, experiences a wide range of surface water temperatures through the year. In spring the lake typically runs cool, often between about 40–55°F (4–13°C) as snowmelt and runoff dominate. Surface temperatures peak in summer, commonly ranging from roughly 60–75°F (16–24°C) on warm, shallow shelves and in protected coves; however, deeper water stays substantially colder. By early fall the surface usually cools back into the mid‑40s to low‑60s°F (7–16°C), and in winter the lake approaches freezing in places, with near‑surface temperatures around 32–40°F (0–4°C) where ice and cold inflows are present. These figures are approximate and vary with weather, wind, inflow from the Bighorn River and the specific location on the reservoir.
Swimming is generally permitted in the Bighorn Lake recreation area because it is a public reservoir used for boating, fishing and day‑use recreation, but conditions govern where and when it is sensible to enter the water. Cold water, sudden depth changes, underwater hazards and boat traffic pose real risks; even in summer, cold shocks and hypothermia can occur if swimmers venture into deeper or moving water. Local signs, posted restrictions and common‑sense precautions—wearing a life jacket, staying near shore and avoiding heavy boat channels—are important for safe swimming.