Water temperature in Lisbon in August

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Is it warm enough to swim in Lisbon in August? Average water temperature in Lisbon in August is 18.1°C and therefore is not suitable for comfortable swimming. The warmest sea in Lisbon in August is 20.1°C, and the coldest is 15.5°C. Average high air temperature in Lisbon in August is 28°C, and average low temperature is 19°C. To find out the sea temperature today and in the coming days, go to Current sea temperature in Lisbon

Changes water temperature in Lisbon in August 2025, 2024

To get an accurate forecast for the water temperature in Lisbon for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Lisbon, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of August.

Sea temperature

Tides

Weather forecast

You can choose any other years:

Day	2025	2024	Min	Max
1 August	18.5°C	18.4°C	16.5°C	19.4°C
2 August	19°C	18°C	15.8°C	19.4°C
3 August	19.1°C	17.7°C	16.2°C	19.3°C
4 August	19.9°C	18.1°C	16.5°C	19.9°C
5 August	19.6°C	18.2°C	16.3°C	19.6°C
6 August	19.1°C	17.7°C	16.6°C	19.1°C
7 August	19.2°C	17.3°C	17.1°C	19.2°C
8 August	19.1°C	17.5°C	16.2°C	19.1°C
9 August	19.3°C	17.8°C	16.4°C	19.7°C
10 August	19.3°C	18.1°C	16.2°C	19.7°C
11 August	20.4°C	18.2°C	16.4°C	20.4°C
12 August	20.2°C	18.6°C	16.3°C	20.2°C
13 August	20.1°C	18.4°C	16.1°C	20.1°C
14 August	20.7°C	17.9°C	15.5°C	20.7°C
15 August	20.2°C	18.2°C	16.3°C	20.2°C

Day	2025	2024	Min	Max
16 August	20.3°C	18.8°C	16.9°C	20.3°C
17 August	19.9°C	18.3°C	16.1°C	19.9°C
18 August	19.4°C	18.1°C	16°C	19.9°C
19 August	18.8°C	17.4°C	16.3°C	20°C
20 August	18.3°C	16.9°C	16.1°C	19.9°C
21 August	18.2°C	16.3°C	16.3°C	19.9°C
22 August	18.4°C	16.2°C	15.7°C	19.9°C
23 August	18.3°C	16.2°C	16.2°C	20°C
24 August	18.6°C	16.8°C	16.7°C	19.9°C
25 August	18.4°C	16.4°C	16.4°C	20.1°C
26 August	17.8°C	16.5°C	16.5°C	19.7°C
27 August	17.2°C	16.6°C	16.6°C	20.1°C
28 August	17.1°C	16.9°C	16.9°C	19.7°C
29 August	17.7°C	16.9°C	16.2°C	19.7°C
30 August	18.2°C	16.8°C	16.1°C	19.6°C
31 August	17.6°C	17.3°C	16.5°C	19.5°C

Average water temperature in Lisbon in August over a decade

2016	2017	2018	2019	2020
19°C	17.3°C	18.1°C	17.2°C	18.8°C

2021	2022	2023	2024	2025
17.3°C	18°C	17.8°C	17.5°C	19.2°C

Lisbon sea state in August

Chart comparing the height of waves in Lisbon in August over the past years. The red line indicates the height of the waves when swimming in the sea is prohibited. To view the current sea conditions, click on the graph.

Weather and climate in Lisbon in August

This data display average monthly climate indicators in Lisbon in August based on our historical weather readings over a period of ten years. In addition to temperature, we include data on the number of rainy and sunny days so you can have all the information about your destination before your trip

Average HIGH temperature28°C
Average LOW temperature19°C
Average rainfall days2 days
Average rainfall0.2''/5mm
Average daylight14h
Average sunshine11h
Average UV index8

Lisbon water temperature during other months:

You can also view information about water temperature for other months by clicking on the month button below

Temperature in neighboring cities

The nearest locations with the average water temperature in August. In addition, the maximum and minimum water temperatures for that month, recorded over the last decade, are shown

	Avr	Min	Max
Costa da Caparica	18.3°C	15.7°C	20.6°C
Trafaria	18.3°C	15.7°C	20.6°C
Santo Amaro	18.3°C	15.7°C	20.6°C
Carcavelos	18.2°C	15.7°C	20.7°C
Parede	18.2°C	15.7°C	20.7°C
Estoril	18°C	15.6°C	20.1°C
Cascais	17.9°C	15.2°C	20.1°C
Paco de Arcos	18.4°C	15.7°C	21.2°C
Alges	18.7°C	15.7°C	22°C
Amadora	18.7°C	15.7°C	22°C

Lisbon photo gallery

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Our report for Lisbon is compiled using satellite data together with in-situ observations to get the most reliable daily data of sea surface temperatures, surf forecasts, current temperatures and weather forecasts.

Region

Date (day and month)

Water temperature: min 16°C

Average temperature Maximum temperature