Lisbon
Portugal
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Lisbon, Portugal

The beautiful hillside city of Lisbon in Portugal, with a high, far view of the Sao Jorge Castle
The beautiful hillside city of Lisbon in Portugal, with a high, far view of the Sao Jorge Castle
The mean September temperature is 22.2°C (72°F), the sea water's 18.9°C (66°F), and the sky is primarily clear. The days are long and warm.
September is a great time to be hanging around the city's miradouros (viewpoints). Windsurfing at Costa da Caparica is an ideal activity at this time of year.

What is the temperature in September in Lisbon?

The average high-temperature, in September, in Lisbon, is 26.5°C (79.7°F), while the average low-temperature is 17.6°C (63.7°F).

How many days does it rain in September in Lisbon?

In September, the rain falls for 6 days. Throughout September, 32.9mm (1.3") of precipitation is accumulated.

When is the sea warmest in Lisbon?

The month with the warmest seawater in Lisbon, Portugal, is September, with an average sea temperature of 19.9°C (67.8°F). For swimming, a surface water temperature of 19.9°C (67.8°F) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 21°C (69.8°F).

What is the sea water temperature in September in Lisbon?

In Lisbon, Portugal, in September, the average water temperature is 19.9°C (67.8°F). Swimming in 19.9°C (67.8°F) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 21°C (69.8°F).

What is the average length of the day in September in Lisbon?

The average length of the day in September in Lisbon, Portugal, is 12.4h.

How long on average sun shines in September in Lisbon?

In September, the average sunshine in Lisbon is 9h.

What is the UV index intensity in September in Lisbon?

The average daily maximum UV index in September in Lisbon is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unprotected exposure to the UV radiation.
Average temperature in September - Lisbon, Portugal
  • Average high temperature in September: 26.5°C

The warmest month (with the highest average high temperature) is August (28.3°C).
The month with the lowest average high temperature is January (14.8°C).

  • Average low temperature in September: 17.6°C

The month with the highest average low temperature is August (18.6°C).
The coldest month (with the lowest average low temperature) is January (8.3°C).

Average rainfall in September - Lisbon, Portugal
  • Average rainfall in September: 32.9mm

The wettest month (with the highest rainfall) is November (127.6mm).
The driest month (with the lowest rainfall) is July (4.2mm).

Average rainfall days in September - Lisbon, Portugal
  • Average rainfall days in September: 6 days

Months with the highest number of rainy days are January, February and December (14 days).
Months with the lowest number of rainy days are July and August (2 days).

Average sea temperature in September - Lisbon, Portugal
  • Average sea temperature in September: 19.9°C

The best month for swimming (with the highest average sea temperature) is September (19.9°C).
The coldest month (with the lowest average sea temperature) is March (15.1°C).

Average daylight in September / Average sunshine in September - Lisbon, Portugal
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.8h).
The month with shortest days is December (Average daylight: 9.5h).

  • Average sunshine in September: 9h

Months with most sunshine are July and August (Average sunshine: 11h).
Months with least sunshine are January, February, November and December (Average sunshine: 5).

Average UV index in September - Lisbon, Portugal
  • Average UV index in September: 6

Months with the highest UV index are June and July (UV index 9).
Months with the lowest UV index are January and December (UV index 2).