Lake McDonald — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake McDonald, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake McDonald today is 14.8°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 54°F (12°C) to 60°F (15°C). The water is significantly warmer, and swimming becomes possible for most people. However, caution may still be required for prolonged stays in the water, as extended exposure can cause discomfort. This is a suitable temperature range for short swims and for those accustomed to cooler water. For more comfortable swimming, it is recommended to use proper gear. 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 |
|---|---|---|---|
| JUN 23 | 14.3°C | 14.0°C | |
| JUN 24 | 14.0°C | 14.0°C | |
| JUN 25 | 13.8°C | 14.0°C | |
| JUN 26 | 14.4°C | 14.0°C | |
| JUN 27 | 15.0°C | 14.0°C | |
| JUN 28 | 14.8°C | 14.0°C | |
| JUN 29 | 14.8°C | 14.0°C | |
| JUN 30 | 14.7°C | 14.0°C | |
| JUL 1 | 18.9°C | 15.0°C | |
| JUL 2 | 18.9°C | 15.2°C | |
| JUL 3 | 18.9°C | 15.4°C | |
| JUL 4 | 18.9°C | 15.6°C | |
| JUL 5 | 18.9°C | 15.8°C | |
| JUL 6 | 18.9°C | 16.0°C | |
| JUL 7 | 18.9°C | 16.2°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 | 2°C | 5°C |
| February | 0°C | 3°C | 5°C |
| March | 1°C | 3°C | 6°C |
| April | 1°C | 4°C | 7°C |
| May | 3°C | 9°C | 15°C |
| June | 10°C | 14°C | 18°C |
| July | 16°C | 19°C | 21°C |
| August | 17°C | 21°C | 25°C |
| September | 14°C | 17°C | 20°C |
| October | 6°C | 11°C | 15°C |
| November | 3°C | 6°C | 9°C |
| December | 0°C | 2°C | 5°C |
Lake McDonald: Water Temperature by Location
Lake McDonald: Weather Forecast
July 1
July 2
July 3
July 4
July 5
Location & Local Information
Lake McDonald is fed by snowmelt and mountain streams, so its surface temperatures stay quite cool through the year. In spring (April–June) the lake typically runs from near freezing up to roughly 32–45°F (0–7°C) as ice melts and runoff remains cold. Summer highs in July and August can warm surface water to about 50–65°F (10–18°C) on sunny afternoons, though deeper water remains much colder and winds can lower temperatures quickly. By fall the surface cools back into the mid-30s to low-50s °F (2–10°C) range as air temperatures drop, and in winter the lake is often near freezing or partially ice-covered with surface temperatures around 32°F (0°C) or below.
Swimming is allowed in Glacier National Park but is limited by practical safety concerns rather than strict prohibition. Short swims and quick wading are common in summer, yet the cold water raises a real risk of cold shock and hypothermia even on warm days, so prolonged immersion is dangerous. There are no lifeguards at Lake McDonald, boat traffic and shifting weather can increase hazards, and visitors are advised to exercise caution, wear protective clothing or wetsuits for longer exposure, and avoid swimming alone.