September weather forecast
Lisbon, Portugal

September sees a subtle shift in weather patterns in Lisbon, marking the beginning of the cooling down process. Despite the average temperature falling to 26.5°C (79.7°F), the sun continues to shine bright, albeit for fewer hours. Though the city experiences marginally more rainfall than the previous month, the weather remains conducive for outdoor activities. A dip in sea temperatures may deter beach visits, but the city remains a hub of leisure and enjoyment. The UV index is dropping, indicating shorter daylight hours, but the pleasant weather ensures the tourism industry continues to thrive.

Temperature

Lisbon experiences an average high-temperature of a still warm 26.5°C (79.7°F) in September, marking an insignificant shift from 28.3°C (82.9°F) in August. During September, Lisbon consistently records a temperature low averaging a comfortable 17.6°C (63.7°F).

Rainfall

In Lisbon, Portugal, in September, it is raining for 6 days, with typically 33mm (1.3") of accumulated precipitation. In Lisbon, during the entire year, the rain falls for 112 days and collects up to 774mm (30.47") of precipitation.

Sea temperature

September is the month with the warmest seawater in Lisbon, with an average sea temperature of 19.9°C (67.8°F).
Note: The enjoyment of swimming decreases for most when the surface water temperature is 19.9°C (67.8°F). Breathing control becomes increasingly challenging as temperatures descend below 21°C (69.8°F).

Daylight

In Lisbon, the average length of the day in September is 12h and 26min.
On the first day of September, sunrise is at 07:06 and sunset at 20:06. On the last day of the month, sunrise is at 07:32 and sunset at 19:20 WEST.

Sunshine

The average sunshine in September in Lisbon is 9h.

UV index

In September, the average daily maximum UV index in Lisbon is 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 6 during September translates into the following directions:
Avoid overexposure. Fair-skinned individuals can burn in under 20 minutes. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.