This data the coastal Dundalk ocean water temperature today, tomorrow and the upcoming days. Besides, you can also get information about the weather and surf forecast, as well as the data on sunrise / sunset and moonrise / moonset at a given point on any given day.
Water temperature in Dundalk today is 75.7°F. Based on our historical data over a period of ten years, the warmest water in this day in Dundalk was recorded in 2018 and was 84°F, and the coldest was recorded in 2017 at 73.6°F. Sea water temperature in Dundalk is expected to drop to 75°F in the next 10 days. September average water temperature in Dundalk is 74.8°F, the minimum temperature is 67.3°F, and the maximum is 84.4°F.
The swimming season in Dundalk lasts from June to October. During those months, Dundalk water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Dundalk in winter reaches 39.2°F, in spring 53.1°F, in summer the average temperature rises to 78.1°F, and in autumn it is 64.4°F.
September 5, 2025 |
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today temp |
75.7°F |
September 4, 2025 |
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yesterday temp |
75.6°F |
The ocean salinity in Dundalk is 0.01‰, and the average salinity of the World Ocean is 35‰.
Another important indicators for a comfortable holiday on the beach are the presence and height of the waves, as well as the speed and direction of the wind. Please find below data on the swell size for Dundalk. We calculate the swell size based on the mean wave height (trough to crest) of each third highest wave. For more information on surf forecasts for the next ten days, please visit sea state forecast Dundalk. Data in table shown for September 5, 2025, time in GMT 0 format (you can change the time zone on the sea state forecast page)
0-3 h | 3-6 h | 6-9 h | 9-12 h |
---|---|---|---|
0' 11" | 0' 7" | 0' 5" | 0' 5" |
0.27 m | 0.17 m | 0.13 m | 0.12 m |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
0' 4" | 0' 4" | 1' 0" | 1' 0" |
0.1 m | 0.09 m | 0.31 m | 0.3 m |
Data in a table show Dundalk temperature today (September 5, 2025). For more information and forecast for a few days, go to the weather forecast Dundalk.
0-3 h | 3-6 h | 6-9 h | 9-12 h |
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![]() | ![]() | ![]() | ![]() |
75.4°F | 72.5°F | 69.3°F | 73.4°F |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
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84.7°F | 89.1°F | 85.6°F | 79.9°F |
You may also be interested in other sections of our site for Dundalk: Sunrise and Sunset, Tides
These figures shows the average, minimum and maximum monthly sea temperature in Dundalk. In addition to the table values, the graph below displays of changes average surface temperature during the year. Values are calculated based on the data over the past 10 years. Using them, you can check the water temperature in Dundalk on any day of this period that interests you. Click on the month link and you will see a table for each day, or alternatively you can view the temperature curve of the month and select 2 different years you want to compare, either in a table or as a curve
Month | Avr | Min | Max | |
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January | 37.4°F | 30.7°F | 46°F | cold |
Ocean water temperature in Dundalk in January | ||||
February | 36.7°F | 29.8°F | 46.9°F | cold |
Ocean water temperature in Dundalk in February | ||||
March | 43.3°F | 31.3°F | 56.3°F | cold |
Ocean water temperature in Dundalk in March | ||||
April | 53.2°F | 42.6°F | 64.6°F | cold |
Ocean water temperature in Dundalk in April | ||||
May | 62.8°F | 46°F | 77.2°F | cold |
Ocean water temperature in Dundalk in May | ||||
June | 73.8°F | 64.9°F | 85.5°F | warm |
Ocean water temperature in Dundalk in June | ||||
July | 80.4°F | 72.7°F | 87.6°F | hot |
Ocean water temperature in Dundalk in July | ||||
August | 80.1°F | 75.7°F | 85.1°F | hot |
Ocean water temperature in Dundalk in August | ||||
September | 74.8°F | 67.3°F | 84.4°F | warm |
Ocean water temperature in Dundalk in September | ||||
October | 65.1°F | 55.4°F | 75.2°F | cold |
Ocean water temperature in Dundalk in October | ||||
November | 53.2°F | 41.4°F | 63°F | cold |
Ocean water temperature in Dundalk in November | ||||
December | 43.3°F | 35.8°F | 52.5°F | cold |
Ocean water temperature in Dundalk in December |