Lake Wallula — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Wallula, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Wallula 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 |
|---|---|---|---|
| JUN 3 | 18.6°C | 17.0°C | |
| JUN 4 | 18.9°C | 17.0°C | |
| JUN 5 | 18.8°C | 17.0°C | |
| JUN 6 | 18.7°C | 17.0°C | |
| JUN 7 | 18.3°C | 17.0°C | |
| JUN 8 | 18.6°C | 17.0°C | |
| JUN 10 | 18.3°C | 17.0°C | |
| JUN 11 | 17.0°C | 18.2°C | |
| JUN 12 | 17.0°C | 18.2°C | |
| JUN 13 | 17.0°C | 18.1°C | |
| JUN 14 | 17.0°C | 18.0°C | |
| JUN 15 | 17.0°C | 18.0°C | |
| JUN 16 | 17.0°C | 17.9°C | |
| JUN 17 | 17.0°C | 17.8°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 | 4°C | 7°C |
| February | 0°C | 3°C | 7°C |
| March | 1°C | 5°C | 10°C |
| April | 3°C | 9°C | 15°C |
| May | 7°C | 14°C | 22°C |
| June | 14°C | 17°C | 20°C |
| July | 18°C | 22°C | 25°C |
| August | 21°C | 23°C | 26°C |
| September | 16°C | 20°C | 23°C |
| October | 10°C | 15°C | 20°C |
| November | 5°C | 10°C | 14°C |
| December | 1°C | 5°C | 10°C |
Lake Wallula: Water Temperature by Location
Lake Wallula: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Lake Wallula, the impounded stretch of the Columbia River behind McNary Dam, experiences wide seasonal variation in surface water temperature. In winter months (December–February) surface readings commonly range from about 35–45°F (2–7°C). Spring (March–May) sees a gradual warming to roughly 45–60°F (7–15°C). Summer (June–August) brings the warmest conditions, with typical surface temperatures near 60–75°F (15–24°C), though shallow bays can be a few degrees warmer on hot days. In autumn (September–November) the water cools again, often sitting between 50–65°F (10–18°C). Deeper or faster-moving channels remain cooler year-round than sheltered coves, and short-term spikes or dips can occur with weather, reservoir operations, and inflows.
Swimming is generally permitted in many public access areas around Lake Wallula because the reservoir is used for multiple recreational purposes, but there are important caveats. Swimming is unsafe or restricted near dam infrastructure, boat channels, and some boat ramps due to strong currents, wake hazards, and regulation. Cold water temperatures outside mid-summer raise the risk of cold shock and hypothermia even when air temperatures are warm, so life jackets and caution are advisable. Water quality and algae conditions can vary seasonally, so checking local advisories and posted signs before entering the water is recommended.