Portmore Lough — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Portmore Lough, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Portmore Lough today is 19.7°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 | 21.3°C | 22.0°C | |
| JUL 17 | 21.3°C | 22.0°C | |
| JUL 18 | 21.5°C | 22.0°C | |
| JUL 19 | 21.3°C | 22.0°C | |
| JUL 20 | 21.3°C | 22.0°C | |
| JUL 21 | 20.1°C | 22.0°C | |
| JUL 22 | 20.1°C | 22.0°C | |
| JUL 23 | 19.7°C | 22.0°C | |
| JUL 24 | 22.0°C | 19.8°C | |
| JUL 25 | 22.0°C | 19.9°C | |
| JUL 26 | 22.0°C | 20.0°C | |
| JUL 27 | 22.0°C | 20.2°C | |
| JUL 28 | 22.0°C | 20.3°C | |
| JUL 29 | 22.0°C | 20.4°C | |
| JUL 30 | 22.0°C | 20.5°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 | 1°C | 5°C | 8°C |
| February | 1°C | 5°C | 8°C |
| March | 3°C | 7°C | 10°C |
| April | 6°C | 10°C | 13°C |
| May | 10°C | 15°C | 21°C |
| June | 13°C | 20°C | 26°C |
| July | 16°C | 22°C | 27°C |
| August | 17°C | 22°C | 27°C |
| September | 13°C | 19°C | 24°C |
| October | 9°C | 13°C | 17°C |
| November | 5°C | 9°C | 12°C |
| December | 3°C | 6°C | 9°C |
Portmore Lough: Water Temperature by Location
Portmore Lough: Weather Forecast
July 24
July 25
July 26
July 27
Location & Local Information
Portmore Lough, located in County Antrim in Northern Ireland, is a shallow freshwater lake surrounded by wetlands and reed beds that form part of a protected nature reserve. Because of its shallow depth, the lake’s water temperature changes more rapidly than that of deeper lakes nearby. In winter, it usually stays around 4–6°C (39–43°F), while in summer it can warm to about 15–18°C (59–64°F). During occasional heatwaves, surface waters may briefly reach 19°C (66°F), especially in calm, sheltered areas. Despite these relatively pleasant summer temperatures, the lake’s ecological importance and soft, marshy banks make it less suited to recreational swimming than to nature observation and conservation.
Swimming is not permitted in Portmore Lough, as the area is managed by the Royal Society for the Protection of Birds (RSPB) as a wildlife sanctuary. The shallow margins, dense reeds, and muddy bottom make it unsafe for bathing, but the site offers excellent opportunities for birdwatching and quiet walks. Visitors can explore the reserve’s circular trail and viewing hides, which overlook flocks of swans, geese, and wading birds throughout the year. The nearby town of Crumlin and the wider Lough Neagh region offer other options for boating, fishing, and outdoor recreation in this scenic part of Northern Ireland.