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September Weather in San Antonio, Chile

Last updated: August 22, 2025

In San Antonio, Chile, the average temperature in September hovers around 11°C (53°F), with a minimum of 5°C (40°F) and a maximum reaching 22°C (72°F). Expect a modest precipitation of 16 mm (0.6 in) over 2 days, and enjoy relatively comfortable conditions with an average humidity of 56%.

September Temperature in San Antonio

In September in San Antonio, the average temperature is 11°C (53°F). Maximums can reach 22°C (72°F), and minimums can be as low as 5°C (40°F). Pack layers to stay comfortable during your travels!

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

The chart illustrates September temperature patterns in San Antonio, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Antonio, September typically has an average temperature of 11°C (53°F), with highs reaching up to 22°C (72°F) and lows dropping to around 5°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec626260575451505053555960
Data source: Temperature data for San Antonio 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 Antonio

In San Antonio in September, the precipitation amount is 16 mm (0.6 in) over a period of 2 days.

September Precipitation Trends in San Antonio

The chart displays monthly precipitation patterns in San Antonio, 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 Antonio, September typically receives around 16 mm (0.6 inches) of precipitation spread over approximately 2 days.
JanFebMarAprMayJunJulAugSepOctNovDec6339431074738161431
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Antonio

In San Antonio in September humidity is 56%. With an average temperature of 11°C (53°F), this humidity feels like a cool, crisp embrace that invigorates your senses while traveling, making each breath refreshing yet slightly heavy in the air, ideal for exploring without feeling overheated.

September Average Humidity in San Antonio

This chart illustrates the average monthly humidity levels in San Antonio, 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 Antonio is approximately 56%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec41%41%46%52%64%71%75%73%56%61%52%39%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Antonio

In San Antonio 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 San Antonio.

Maximum UV Index Levels in San Antonio for September

The chart shows the monthly maximum UV Index (UVI) for San Antonio 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 Antonio typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec141311853468111314
Data source: San Antonio 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 Antonio Compares to Other Months

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

This table compares monthly weather conditions in San Antonio, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather17°C (62°F)6 mm (0.2 inches)41%extreme
February Weather17°C (62°F)3 mm (0.1 inches)41%extreme
March Weather16°C (60°F)3 mm (0.1 inches)46%extreme
April Weather14°C (57°F)9 mm (0.4 inches)52%very high
May Weather12°C (54°F)43 mm (1.7 inches)64%moderate
June Weather11°C (51°F)107 mm (4.2 inches)71%moderate
July Weather10°C (50°F)47 mm (1.9 inches)75%moderate
August Weather10°C (51°F)38 mm (1.5 inches)73%high
September Weather11°C (53°F)16 mm (0.6 inches)56%very high
October Weather13°C (55°F)14 mm (0.6 inches)61%extreme
November Weather15°C (59°F)3 mm (0.1 inches)52%extreme
December Weather16°C (61°F)1 mm (0.0 inches)39%extreme

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