Spelga Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Spelga Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Spelga Reservoir today is 14.7°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 |
|---|---|---|---|
| AUG 26 | 14.8°C | 20.4°C | |
| AUG 27 | 15.1°C | 20.4°C | |
| AUG 28 | 15.4°C | 20.4°C | |
| AUG 29 | 15.4°C | 20.4°C | |
| AUG 30 | 15.8°C | 20.4°C | |
| AUG 31 | 15.9°C | 20.4°C | |
| SEP 1 | 15.3°C | 18.0°C | |
| SEP 2 | 15.8°C | 18.0°C | |
| SEP 3 | 18.0°C | 14.9°C | |
| SEP 4 | 18.0°C | 15.0°C | |
| SEP 5 | 18.0°C | 15.2°C | |
| SEP 6 | 18.0°C | 15.4°C | |
| SEP 7 | 18.0°C | 15.5°C | |
| SEP 8 | 18.0°C | 15.7°C | |
| SEP 9 | 18.0°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 | 4°C | 7°C |
| February | 0°C | 4°C | 7°C |
| March | 2°C | 6°C | 9°C |
| April | 5°C | 9°C | 12°C |
| May | 9°C | 14°C | 20°C |
| June | 12°C | 19°C | 25°C |
| July | 15°C | 21°C | 26°C |
| August | 14°C | 20°C | 26°C |
| September | 12°C | 18°C | 23°C |
| October | 8°C | 12°C | 15°C |
| November | 4°C | 8°C | 11°C |
| December | 0°C | 3°C | 7°C |
Spelga Reservoir: Water Temperature by Location
Spelga Reservoir: Weather Forecast
September 3
September 4
September 5
September 6
September 7
September 8
Location & Local Information
Spelga Reservoir lies high in the Mourne Mountains of County Down, surrounded by rugged hills and open moorland that give it a striking, isolated beauty. Because of its elevation, the water here stays particularly cold throughout the year. In winter, temperatures often hover around 3–5 °C (37–41 °F), and even in late spring they rarely rise above 10 °C (50 °F). During the short summer season, surface temperatures may reach 13–15 °C (55–59 °F) on sunny days, though the deeper layers remain much colder. By autumn, cooling winds and rainfall quickly lower the water temperature again to near 8 °C (46 °F), making the reservoir one of the chilliest bodies of water in Northern Ireland.
Swimming in Spelga Reservoir is not officially permitted, as it serves as part of the regional water supply and safety restrictions are in place. The cold temperatures, steep banks, and sudden depth changes also make it unsuitable for casual bathing. However, the area around the reservoir is popular with walkers, cyclists, and photographers drawn by the dramatic mountain scenery. Visitors can enjoy the panoramic views from the dam or explore nearby attractions such as Silent Valley Reservoir, Tollymore Forest Park, and the peaks of Slieve Binnian and Slieve Muck, all within a short distance.