September Weather in San Fernando, Mexico

Last updated: August 27, 2025

In September, the average temperature in San Fernando, Mexico hovers around 23°C (74°F). Expect a comfortable minimum of 18°C (64°F), with highs reaching up to 32°C (90°F). However, be prepared for some rain, as the area sees an average precipitation of 344 mm (13.5 in) over 29 days. Don't forget to account for the humidity, which averages a sticky 84%!

September Temperature in San Fernando

In September in San Fernando, the average temperature is 23°C (74°F). Maximum temperatures can reach 32°C (90°F), while minimums can drop to as low as 18°C (64°F). This pleasant climate makes San Fernando an ideal destination for travelers looking to enjoy mild weather and outdoor activities.

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 (74°F), with highs reaching up to 32°C (90°F) and lows dropping to around 18°C (64°F).

Data source: Temperature data for San Fernando generated using information from the Copernicus Climate Change Service.

September Precipitation in San Fernando

In San Fernando in September, the total precipitation amount is 344 mm (13.5 in) over the course of 29 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 344 mm (13.5 inches) of precipitation spread over approximately 29 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in San Fernando

In San Fernando in September, humidity is 84%. With an average temperature of 23°C (74°F), this humidity feels like a warm blanket wrapping around you, making outdoor activities feel sticky and heavy, while the air's thickness can be quite exhausting for long periods of travel.

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 84%, offering insight into how humid the weather typically is during this month.

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 13, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to take protective measures. For 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 13, which falls under the extreme exposure category.

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.
	Temperature	Precipitation	Humidity	UV
January Weather	18°C (65°F)	28 mm (1.1 inches)	64%	very high
February Weather	19°C (66°F)	39 mm (1.5 inches)	57%	very high
March Weather	20°C (69°F)	2 mm (0.1 inches)	46%	extreme
April Weather	21°C (71°F)	1 mm (0.0 inches)	42%	extreme
May Weather	23°C (74°F)	9 mm (0.3 inches)	51%	extreme
June Weather	24°C (76°F)	146 mm (5.7 inches)	74%	extreme
July Weather	24°C (75°F)	289 mm (11.4 inches)	79%	extreme
August Weather	24°C (75°F)	313 mm (12.3 inches)	81%	extreme
September Weather	23°C (74°F)	344 mm (13.5 inches)	84%	extreme
October Weather	23°C (74°F)	153 mm (6.0 inches)	75%	extreme
November Weather	21°C (70°F)	24 mm (0.9 inches)	71%	very high
December Weather	19°C (66°F)	26 mm (1.0 inches)	74%	high