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September Weather in San Sebastian, Philippines

Last updated: August 27, 2025

In September, the average temperature in San Sebastian, Philippines hovers around 27°C (81°F). Expect minimums of 23°C (74°F) and highs reaching up to 32°C (90°F). The region experiences significant rainfall, with 251 mm (9.9 in) spread across 27 days. Prepare for a humid environment, as the average humidity stands at a noteworthy 90%.

September Temperature in San Sebastian

In September in San Sebastian, the average temperature is 27°C (81°F). Maximums can reach 32°C (90°F) and minimums can be as low as 23°C (74°F). This pleasant climate makes San Sebastian a great destination for travelers looking to enjoy warm and comfortable weather.

September Weather in San Sebastian: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in San Sebastian, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Sebastian, September typically has an average temperature of 27°C (81°F), with highs reaching up to 32°C (90°F) and lows dropping to around 23°C (74°F).
JanFebMarAprMayJunJulAugSepOctNovDec797880818282818181818079
Data source: Temperature data for San Sebastian 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 San Sebastian

In San Sebastian in September, the precipitation amount is 251 mm (9.9 in) over the course of 27 days.

September Precipitation Trends in San Sebastian

The chart displays monthly precipitation patterns in San Sebastian, 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 San Sebastian, September typically receives around 251 mm (9.9 inches) of precipitation spread over approximately 27 days.
JanFebMarAprMayJunJulAugSepOctNovDec17611686124122261316260251263185296
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Sebastian

In San Sebastian in September, humidity is 90%. With an average temperature of 27°C (81°F), this humidity feels like walking through a heavy fog, making outdoor activities uncomfortable and exhausting, and leaving travelers drenched in sweat within minutes.

September Average Humidity in San Sebastian

This chart illustrates the average monthly humidity levels in San Sebastian, 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 San Sebastian is approximately 90%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%80%77%78%85%87%88%89%90%87%90%91%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Sebastian

In San Sebastian in September, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in San Sebastian, you can check here.

Maximum UV Index Levels in San Sebastian for September

The chart shows the monthly maximum UV Index (UVI) for San Sebastian 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 San Sebastian typically reaches 14, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec121316161414131414141211
Data source: San Sebastian 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 San Sebastian Compares to Other Months

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

This table compares monthly weather conditions in San Sebastian, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather26°C (79°F)176 mm (6.9 inches)85%extreme
February Weather26°C (79°F)116 mm (4.6 inches)80%extreme
March Weather27°C (80°F)86 mm (3.4 inches)77%extreme
April Weather27°C (81°F)124 mm (4.9 inches)78%extreme
May Weather28°C (83°F)121 mm (4.8 inches)84%extreme
June Weather28°C (82°F)261 mm (10.3 inches)87%extreme
July Weather27°C (81°F)316 mm (12.4 inches)88%extreme
August Weather27°C (82°F)260 mm (10.2 inches)89%extreme
September Weather27°C (81°F)251 mm (9.9 inches)90%extreme
October Weather27°C (81°F)263 mm (10.4 inches)87%extreme
November Weather27°C (81°F)185 mm (7.3 inches)90%extreme
December Weather26°C (80°F)296 mm (11.7 inches)91%extreme

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