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September Weather in Lisbon, United States

Last updated: June 24, 2025

In September, the average temperature in Lisbon, United States hovers around 19°C (67°F), with a minimum of 5°C (42°F) and a maximum reaching up to 33°C (91°F). Visitors should prepare for a fair amount of rainfall, as the area sees approximately 96 mm (3.8 in) of precipitation spread over 9 days. Additionally, expect a comfortable average humidity of 75% during this month, making it a pleasantly refreshing time to explore!

September Temperature in Lisbon

In September in Lisbon, the average temperature is 19°C (67°F). The maximum can reach 33°C (91°F), and the minimum can be as low as 5°C (42°F). This diverse temperature range makes Lisbon an ideal destination for travelers seeking both warmth and cooler evenings.

September Weather in Lisbon: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Lisbon, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lisbon, September typically has an average temperature of 19°C (67°F), with highs reaching up to 33°C (91°F) and lows dropping to around 5°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec323439495968747367574436
Data source: Temperature data for Lisbon generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Lisbon

In Lisbon in September, the total precipitation amount is 96 mm (3.8 in) spread over a period of 9 days.

September Precipitation Trends in Lisbon

The chart displays monthly precipitation patterns in Lisbon, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Lisbon, September typically receives around 96 mm (3.8 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec7292981291099614911196132101130
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Lisbon

In Lisbon in September humidity is 75%. With an average temperature of 19°C (67°F), this humidity feels like a warm embrace, making travel invigorating yet slightly sticky, as you navigate through the vibrant streets or scenic landscapes.

September Average Humidity in Lisbon

This chart illustrates the average monthly humidity levels in Lisbon, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Lisbon is approximately 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%84%82%79%75%78%76%76%76%75%80%80%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Lisbon

In Lisbon in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Lisbon.

Maximum UV Index Levels in Lisbon for September

The chart shows the monthly maximum UV Index (UVI) for Lisbon in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Lisbon typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3568910998642
Data source: Lisbon September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Lisbon Compares to Other Months

Weather in Lisbon varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Lisbon, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Lisbon, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (33°F)72 mm (2.8 inches)84%moderate
February Weather1°C (35°F)92 mm (3.6 inches)84%moderate
March Weather4°C (40°F)98 mm (3.8 inches)82%high
April Weather9°C (49°F)129 mm (5.1 inches)79%very high
May Weather15°C (59°F)109 mm (4.3 inches)75%very high
June Weather20°C (68°F)96 mm (3.8 inches)78%very high
July Weather23°C (75°F)149 mm (5.8 inches)76%very high
August Weather23°C (74°F)111 mm (4.4 inches)76%very high
September Weather19°C (67°F)96 mm (3.8 inches)75%very high
October Weather14°C (58°F)132 mm (5.2 inches)75%high
November Weather7°C (45°F)101 mm (4.0 inches)80%moderate
December Weather2°C (36°F)130 mm (5.1 inches)80%low

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