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September Weather in San Fernando, Mexico

Last updated: August 27, 2025

In San Fernando, Mexico, the average temperature in September reaches a balmy 28°C (83°F), with minimums dropping to 19°C (66°F) and maximums soaring to 39°C (103°F). Expect 109 mm (4.3 in) of precipitation over 13 days, accompanied by a high average humidity of 75%. Whether you're exploring the vibrant streets or soaking in the local culture, be prepared for a warm and humid experience!

September Temperature in San Fernando

In September in San Fernando, the average temperature is 28°C (83°F), with maximums reaching 39°C (103°F) and minimums dropping as low as 19°C (66°F). Be sure to pack light clothing and stay hydrated while enjoying your travels!

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 28°C (83°F), with highs reaching up to 39°C (103°F) and lows dropping to around 19°C (66°F).
JanFebMarAprMayJunJulAugSepOctNovDec636672778285858782776965
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 109 mm (4.3 in), which occurs during 13 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 109 mm (4.3 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec2416363058738625109873313
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 75%. With an average temperature of 28°C (83°F), this humidity feels like a warm blanket enveloping you, making outdoor activities feel particularly heavy, and prompting frequent breaks in the shade to stay comfortable while traveling.

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 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%83%78%81%82%74%68%67%75%78%83%86%
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 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, 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 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec79111212121212111086
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 Weather17°C (63°F)24 mm (0.9 inches)84%high
February Weather19°C (67°F)16 mm (0.6 inches)83%very high
March Weather22°C (73°F)36 mm (1.4 inches)78%extreme
April Weather25°C (78°F)30 mm (1.2 inches)81%extreme
May Weather28°C (83°F)58 mm (2.3 inches)82%extreme
June Weather29°C (85°F)72 mm (2.9 inches)74%extreme
July Weather30°C (86°F)86 mm (3.4 inches)68%extreme
August Weather30°C (87°F)25 mm (1.0 inches)67%extreme
September Weather28°C (83°F)109 mm (4.3 inches)75%extreme
October Weather25°C (77°F)87 mm (3.4 inches)78%very high
November Weather21°C (70°F)33 mm (1.3 inches)83%very high
December Weather18°C (66°F)13 mm (0.5 inches)86%high

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