Lake Llyn Celyn — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Llyn Celyn, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Llyn Celyn today is 14°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 3 | 13.8°C | 19.5°C | |
| JUN 4 | 13.8°C | 19.5°C | |
| JUN 5 | 13.8°C | 19.5°C | |
| JUN 6 | 13.8°C | 19.5°C | |
| JUN 7 | 14.0°C | 19.5°C | |
| JUN 8 | 14.0°C | 19.5°C | |
| JUN 10 | 14.0°C | 19.5°C | |
| JUN 11 | 19.5°C | 14.3°C | |
| JUN 12 | 19.5°C | 14.6°C | |
| JUN 13 | 19.5°C | 14.8°C | |
| JUN 14 | 19.5°C | 15.1°C | |
| JUN 15 | 19.5°C | 15.4°C | |
| JUN 16 | 19.5°C | 15.7°C | |
| JUN 17 | 19.5°C | 15.9°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 | 6°C |
| February | 0°C | 4°C | 7°C |
| March | 2°C | 6°C | 9°C |
| April | 6°C | 10°C | 13°C |
| May | 9°C | 16°C | 22°C |
| June | 13°C | 20°C | 25°C |
| July | 16°C | 21°C | 26°C |
| August | 16°C | 21°C | 26°C |
| September | 11°C | 17°C | 22°C |
| October | 8°C | 12°C | 15°C |
| November | 3°C | 7°C | 10°C |
| December | 0°C | 4°C | 7°C |
Lake Llyn Celyn: Water Temperature by Location
Lake Llyn Celyn: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Llyn Celyn is a large reservoir in Snowdonia, North Wales, known for its dramatic and often controversial creation. As it is a working reservoir, swimming is generally prohibited by the managing authorities due to significant inherent dangers and the need to protect the water supply. The lake water is exceptionally cold and deep, presenting a major risk of cold water shock and hypothermia even for strong swimmers. Seasonal surface water temperatures in this upland location rarely rise above 14∘C to 17∘C (57∘F to 63∘F) in the height of summer, and they drop to frigid levels between 4∘C and 8∘C (39∘F to 46∘F) during the winter months.
While swimming is discouraged, the lake is a popular spot for other watersports, particularly canoeing and kayaking, which are typically permitted with the appropriate licenses and safety precautions. The area is part of the beautiful Eryri (Snowdonia) National Park, with nearby attractions including the scenic Llyn Tegid (Bala Lake) which offers more permitted watersports, and the historic town of Bala, known for its Welsh culture and outdoor adventure centres.