Willamette Slough Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Willamette Slough Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Willamette Slough Lake today is 25.9°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 75°F (23°C) to 79°F (26°C). This is a very comfortable temperature for swimming, and many people can enjoy prolonged stays in the water without feeling cold. The water is pleasantly warm, making it ideal for relaxation and water sports. This temperature range is particularly popular among tourists, as it combines comfort and safety for health. 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 4 | 22.6°C | 24.0°C | |
| AUG 5 | 23.1°C | 24.0°C | |
| AUG 6 | 23.4°C | 24.0°C | |
| AUG 7 | 25.4°C | 24.0°C | |
| AUG 8 | 25.5°C | 24.0°C | |
| AUG 9 | 26.2°C | 24.0°C | |
| AUG 10 | 26.2°C | 24.0°C | |
| AUG 11 | 26.0°C | 24.0°C | |
| AUG 12 | 24.0°C | 25.8°C | |
| AUG 13 | 24.0°C | 25.7°C | |
| AUG 14 | 24.0°C | 25.6°C | |
| AUG 15 | 24.0°C | 25.5°C | |
| AUG 16 | 24.0°C | 25.4°C | |
| AUG 17 | 24.0°C | 25.3°C | |
| AUG 18 | 24.0°C | 25.2°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 | 4°C | 9°C |
| February | 0°C | 4°C | 9°C |
| March | 1°C | 6°C | 12°C |
| April | 8°C | 12°C | 15°C |
| May | 13°C | 17°C | 21°C |
| June | 15°C | 19°C | 23°C |
| July | 17°C | 22°C | 26°C |
| August | 21°C | 24°C | 27°C |
| September | 17°C | 20°C | 23°C |
| October | 10°C | 14°C | 17°C |
| November | 4°C | 9°C | 13°C |
| December | 5°C | 8°C | 12°C |
Willamette Slough Lake: Water Temperature by Location
Willamette Slough Lake: Weather Forecast
August 12
August 13
August 14
August 15
Location & Local Information
Willamette Slough and the small backwater lakes and side channels around it tend to be cooler than shallow inland ponds, especially where there is river flow and shade from riparian trees. Typical seasonal surface-temperature ranges for these slough and oxbow lakes are roughly 35–45°F (2–7°C) in winter, 45–60°F (7–16°C) in spring, 60–75°F (16–24°C) in summer and 50–65°F (10–18°C) in autumn. Local conditions can move those numbers up or down: shallow, sun-warmed stretches can reach the upper end of the summer range, while spring runoff and deeper channels stay markedly colder. Temperature stratification is usually modest because sloughs are relatively shallow and mixed by wind and current.
Swimming is physically possible in summer when surface temperatures are warmest, but whether it is advisable or permitted depends on access, signage and water-quality conditions. Many spots have no lifeguards, limited official beach facilities and occasional advisories for bacteria or cyanobacteria blooms after warm, stagnant periods. Even in summer, cold pockets, submerged debris and variable currents pose safety risks, and in shoulder seasons the danger of cold-water shock is real. For safe recreation, check local notices, avoid areas with warning signs and exercise caution when entering unfamiliar slough waters.