This data the coastal Penn Lann sea 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 Penn Lann today is 19.1°C. Based on our historical data over a period of ten years, the warmest water in this day in the Bay of Biscay near Penn Lann was recorded in 2022 and was 21°C, and the coldest was recorded in 2007 at 16.9°C. Sea water temperature in Penn Lann is expected to drop to 17.9°C in the next 10 days. September average water temperature in Penn Lann is 17.9°C, the minimum temperature is 15.3°C, and the maximum is 21.2°C.
The swimming season in Penn Lann lasts only one month - August. During this month, Penn Lann water temperature does not drop below 20°C and therefore suitable for comfortable swimming. The average water temperature in Penn Lann in winter reaches 9.4°C, in spring 12.2°C, in summer the average temperature rises to 18.4°C, and in autumn it is 15.6°C.
5 September 2025 |
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today temp |
19.1°C |
4 September 2025 |
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yesterday temp |
19.4°C |
The sea salinity in Penn Lann is 30.25‰, 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 Penn Lann. 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 Penn Lann. Data in table shown for 5 September 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 |
---|---|---|---|
2' 4" | 2' 1" | 1' 10" | 1' 8" |
0.72 m | 0.64 m | 0.57 m | 0.52 m |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
1' 7" | 1' 5" | 1' 3" | 1' 2" |
0.47 m | 0.43 m | 0.39 m | 0.35 m |
Data in a table show Penn Lann temperature today (5 September 2025). For more information and forecast for a few days, go to the weather forecast Penn Lann.
0-3 h | 3-6 h | 6-9 h | 9-12 h |
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![]() | ![]() | ![]() | ![]() |
14.9°C | 13.5°C | 12.7°C | 16.4°C |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
![]() | ![]() | ![]() | ![]() |
19.7°C | 20.6°C | 19.1°C | 15.5°C |
You may also be interested in other sections of our site for Penn Lann: Sunrise and Sunset, Tides
These figures shows the average, minimum and maximum monthly sea temperature in Penn Lann. 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 Penn Lann 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 | 9°C | 6.5°C | 11.8°C | cold |
Sea water temperature in Penn Lann in January | ||||
February | 8.7°C | 6.7°C | 10.6°C | cold |
Sea water temperature in Penn Lann in February | ||||
March | 9.8°C | 7.1°C | 12.3°C | cold |
Sea water temperature in Penn Lann in March | ||||
April | 12.1°C | 8.4°C | 15.6°C | cold |
Sea water temperature in Penn Lann in April | ||||
May | 14.6°C | 11.4°C | 18.5°C | cold |
Sea water temperature in Penn Lann in May | ||||
June | 17.3°C | 13.9°C | 21.7°C | cold |
Sea water temperature in Penn Lann in June | ||||
July | 18.8°C | 16.4°C | 22.6°C | cold |
Sea water temperature in Penn Lann in July | ||||
August | 19.1°C | 17.1°C | 22.2°C | cold |
Sea water temperature in Penn Lann in August | ||||
September | 17.9°C | 15.3°C | 21.2°C | cold |
Sea water temperature in Penn Lann in September | ||||
October | 15.8°C | 13.2°C | 19.5°C | cold |
Sea water temperature in Penn Lann in October | ||||
November | 13.1°C | 10°C | 16.3°C | cold |
Sea water temperature in Penn Lann in November | ||||
December | 10.4°C | 7.9°C | 13.3°C | cold |
Sea water temperature in Penn Lann in December |