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September Weather in San Fernando, United States

Last updated: June 24, 2025

In September, the average temperature in San Fernando, United States is a comfortable 23°C (75°F), making it an ideal time to explore. However, temperatures can vary significantly, with a minimum of 11°C (52°F) and soaring up to a scorching 45°C (113°F). Expect minimal precipitation of just 3 mm (0.1 in) over 0 days, alongside an average humidity level of 48%, ensuring a pleasant climate for outdoor activities.

September Temperature in San Fernando

In September in San Fernando, the average temperature is 23°C (75°F). Maximum temperatures can reach 45°C (113°F), while minimums can drop as low as 11°C (52°F). Travelers should be prepared for a wide range of temperatures, ensuring they pack accordingly for both warm days and cooler nights.

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

The chart illustrates September temperature patterns in San Fernando, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Fernando, September typically has an average temperature of 23°C (75°F), with highs reaching up to 45°C (113°F) and lows dropping to around 11°C (52°F).
JanFebMarAprMayJunJulAugSepOctNovDec545557636571777774686154
Data source: Temperature data for San Fernando 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 Fernando

In San Fernando in September, the precipitation amount is 3 mm (0.1 in) during a total of 0 days.

September Precipitation Trends in San Fernando

The chart displays monthly precipitation patterns in San Fernando, 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 Fernando, September typically receives around 3 mm (0.1 inches) of precipitation spread over approximately 0 days.
JanFebMarAprMayJunJulAugSepOctNovDec7762852015211392084
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Fernando

In San Fernando in September, humidity is 48%. With an average temperature of 23°C (75°F), this humidity feels like a comfortable embrace, making it ideal for exploring the sights and enjoying outdoor activities without feeling overly sticky or oppressive.

September Average Humidity in San Fernando

This chart illustrates the average monthly humidity levels in San Fernando, 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 Fernando is approximately 48%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec78%82%76%68%58%52%46%39%48%59%72%76%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Fernando

In San Fernando in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in San Fernando.

Maximum UV Index Levels in San Fernando for September

The chart shows the monthly maximum UV Index (UVI) for San Fernando 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 Fernando typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468101111121110754
Data source: San Fernando 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 Fernando Compares to Other Months

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

This table compares monthly weather conditions in San Fernando, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather12°C (54°F)77 mm (3.0 inches)78%moderate
February Weather13°C (55°F)62 mm (2.5 inches)82%high
March Weather14°C (57°F)85 mm (3.3 inches)75%very high
April Weather17°C (63°F)20 mm (0.8 inches)68%very high
May Weather18°C (65°F)15 mm (0.6 inches)57%extreme
June Weather22°C (71°F)2 mm (0.1 inches)52%extreme
July Weather25°C (77°F)1 mm (0.0 inches)46%extreme
August Weather25°C (78°F)1 mm (0.0 inches)39%extreme
September Weather23°C (75°F)3 mm (0.1 inches)48%very high
October Weather20°C (69°F)9 mm (0.4 inches)59%high
November Weather16°C (62°F)20 mm (0.8 inches)72%moderate
December Weather12°C (54°F)84 mm (3.3 inches)76%moderate

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