Riffe Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Riffe Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Riffe Lake today is 20.6°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 68°F (20°C) to 74°F (23°C). The water is warm and pleasant for swimming, and in this range, one can stay in the water for extended periods without the risk of hypothermia. This is the ideal temperature for relaxation, swimming, and water sports. Families with children, as well as outdoor enthusiasts, will enjoy swimming and time spent in the water. For most people, this is the optimal temperature for a comfortable beach experience. 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 | 20.7°C | 24.5°C | |
| AUG 25 | 20.3°C | 24.5°C | |
| AUG 26 | 20.3°C | 24.5°C | |
| AUG 27 | 20.3°C | 24.5°C | |
| AUG 28 | 20.4°C | 24.5°C | |
| AUG 29 | 20.9°C | 24.5°C | |
| AUG 30 | 20.9°C | 24.5°C | |
| AUG 31 | 20.6°C | 24.5°C | |
| SEP 1 | 21.5°C | 20.6°C | |
| SEP 2 | 21.5°C | 20.7°C | |
| SEP 3 | 21.5°C | 20.7°C | |
| SEP 4 | 21.5°C | 20.8°C | |
| SEP 5 | 21.5°C | 20.8°C | |
| SEP 6 | 21.5°C | 20.9°C | |
| SEP 7 | 21.5°C | 20.9°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 | 7°C |
| February | 2°C | 5°C | 8°C |
| March | 1°C | 6°C | 11°C |
| April | 3°C | 9°C | 15°C |
| May | 10°C | 16°C | 21°C |
| June | 13°C | 19°C | 24°C |
| July | 15°C | 23°C | 31°C |
| August | 19°C | 25°C | 30°C |
| September | 17°C | 22°C | 26°C |
| October | 11°C | 16°C | 20°C |
| November | 5°C | 10°C | 14°C |
| December | 4°C | 7°C | 9°C |
Riffe Lake: Water Temperature by Location
Riffe Lake: Weather Forecast
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September 6
Location & Local Information
Riffe Lake, a reservoir behind Mossyrock Dam in Washington, exhibits marked seasonal and vertical variation in water temperature. Surface temperatures in summer typically climb into the 60s to lower 70s °F (about 15–22 °C) on the warmest days, while spring and fall surface readings are commonly in the mid‑40s to around 60 °F (roughly 7–16 °C). Winter surface temperatures frequently hover near freezing to the mid‑40s °F (around 0–7 °C). Because it is a deep reservoir, deeper water remains significantly colder year‑round, so thermoclines and cold, dense water at depth can contrast sharply with warmer surface layers.
Swimming is generally permitted at Riffe Lake within managed recreational areas, as the reservoir is used for boating, fishing and water recreation. That said, swimmers should be aware of hazards specific to reservoirs: fluctuating water levels from dam operations, submerged trees and debris, abrupt drop‑offs, boat traffic, and the risk of cold‑water shock even in summer when surface temperatures are modest. There are no widespread lifeguard services, so swimming is safest at designated access points during the warmest months (mid‑summer) and with appropriate precautions such as life jackets and attention to posted restrictions or advisories.