Portnoo — Water Temperature, Sea Conditions & Trends
This page provides clear and up-to-date information about water temperature for Portnoo (Ulster, Republic of Ireland). It includes the current water temperature, daily data for the last month presented in a simple chart, and a 7-day forecast. The page also compares today’s value with typical averages for this period, shows usual monthly ranges during the year, and lists nearby beaches with short descriptions. Local weather for the next few days and general details about Portnoo help you plan your visit and choose the best time for swimming.
Current Water Temperature
Water temperature in Portnoo in the Atlantic Ocean today is 15°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people.
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
Water temperature in Portnoo rose over the last 30 days but fell over the last week. Currently, the sea water at this location is slightly warmer than average for this day in previous years.
According to our forecast, Water temperature in Portnoo will be 14.5°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| JUN 24 | 15.4°C | 8.3°C | |
| JUN 25 | 15.2°C | 9.0°C | |
| JUN 26 | 15.5°C | 10.5°C | |
| JUN 27 | 16.0°C | 10.8°C | |
| JUN 28 | 16.0°C | 13.0°C | |
| JUN 29 | 15.8°C | 12.5°C | |
| JUN 30 | 15.5°C | 14.5°C | |
| JUL 1 | 15.3°C | 14.0°C | |
| JUL 2 | 15.3°C | 14.0°C | 15.3°C |
| JUL 3 | 13.5°C | 15.2°C | |
| JUL 4 | 13.3°C | 15.1°C | |
| JUL 5 | 14.3°C | 14.9°C | |
| JUL 6 | 14.0°C | 14.8°C | |
| JUL 7 | 14.3°C | 14.7°C | |
| JUL 8 | 14.0°C | 14.6°C | |
| JUL 9 | 14.3°C | 14.5°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.
Water temperature data for this location is gathered from various sources, including buoys and satellite sea and ocean surface maps provided by the NOAA agency. We also incorporate data from local authorities in each specific location worldwide to ensure more accurate temperature readings.
Annual Water Temperature Overview by Month
Monthly Water Temp Ranges
Annual Water Temperature Trend
Portnoo is a small coastal village in County Donegal on Ireland’s north‑western Atlantic shore, offering a rugged shoreline of bays, sandy stretches and rock outcrops. Sea temperatures here are cool year‑round due to Atlantic influence. Typical seasonal ranges are: winter roughly 7–10 °C, spring around 8–12 °C, summer generally 12–16 °C, and autumn about 10–13 °C. Local conditions can vary with wind, tides and swell, so short‑term readings may differ from these averages. Water clarity is often good after calm weather, but swells and run‑off after heavy rain can reduce visibility and change local temperatures near the shore.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 7°C | 9°C | 12°C |
| February | 7°C | 9°C | 11°C |
| March | 7°C | 9°C | 11°C |
| April | 8°C | 9°C | 11°C |
| May | 9°C | 11°C | 13°C |
| June | 10°C | 13°C | 17°C |
| July | 12°C | 15°C | 19°C |
| August | 13°C | 15°C | 17°C |
| September | 13°C | 15°C | 17°C |
| October | 11°C | 13°C | 16°C |
| November | 10°C | 12°C | 14°C |
| December | 9°C | 10°C | 12°C |
* Click on a month to view detailed water temperature data.
Portnoo: Weather Forecast
July 3
July 4
July 5
July 6
Location, Beaches & Local Information
Nearby Beaches & Facilities
Narin Beach
Kiltoorish Bay Beach
Ballinreavy Strand
Dooey Beach
Swimming Conditions
Swimming around Portnoo suits people prepared for cool water and variable conditions. Sandy bays and sheltered inlets provide easier entry for casual paddling or supervised family swims in the warmest weeks, while more exposed headlands attract experienced wild swimmers and sea‑kayakers. Many visitors wear wetsuits or drysuits outside mid‑summer when water temperatures typically reach 12–16 °C, and swimmers should be aware that lifeguard cover is limited or seasonal. Checking tides, weather, and local advice before entering the water, using a buddy system and choosing sheltered spots on calm days will improve safety; the coastline also offers coastal walks and rock pools for lower‑intensity beach holidays.