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 19.2°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 |
|---|---|---|---|
| JUL 16 | 20.0°C | 21.0°C | |
| JUL 17 | 19.6°C | 21.0°C | |
| JUL 18 | 19.6°C | 21.0°C | |
| JUL 19 | 19.6°C | 21.0°C | |
| JUL 20 | 19.6°C | 21.0°C | |
| JUL 21 | 19.3°C | 21.0°C | |
| JUL 22 | 19.3°C | 21.0°C | |
| JUL 23 | 19.2°C | 21.0°C | |
| JUL 24 | 21.0°C | 19.3°C | |
| JUL 25 | 21.0°C | 19.4°C | |
| JUL 26 | 21.0°C | 19.5°C | |
| JUL 27 | 21.0°C | 19.6°C | |
| JUL 28 | 21.0°C | 19.7°C | |
| JUL 29 | 21.0°C | 19.7°C | |
| JUL 30 | 21.0°C | 19.8°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 | 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
July 24
July 25
July 26
July 27
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.