September Weather in Santa Rosa (Santa Barbara), Mexico

Last updated: August 27, 2025

In September, the average temperature in Santa Rosa (Santa Barbara), Mexico hovers around 17°C (63°F). During this time, you can expect a minimum of 11°C (52°F) and a maximum of 26°C (80°F). With an average humidity of 85% and 332 mm (13.1 in) of precipitation spread over 28 days, be prepared for a mix of cool and damp conditions throughout the month.

September Temperature in Santa Rosa (Santa Barbara)

In September in Santa Rosa (Santa Barbara), the average temperature is 17°C (63°F). Maximum temperatures can reach 26°C (80°F), while the minimum can drop to as low as 11°C (52°F). This pleasant weather makes Santa Rosa (Santa Barbara) an ideal destination for travelers looking to explore comfortably.

September Weather in Santa Rosa (Santa Barbara): Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Santa Rosa (Santa Barbara), showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santa Rosa (Santa Barbara), September typically has an average temperature of 17°C (63°F), with highs reaching up to 26°C (80°F) and lows dropping to around 11°C (52°F).

Data source: Temperature data for Santa Rosa (Santa Barbara) generated using information from the Copernicus Climate Change Service.

September Precipitation in Santa Rosa (Santa Barbara)

In Santa Rosa (Santa Barbara) in September, the total precipitation amount is 332 mm (13.1 in) recorded over a span of 28 days.

September Precipitation Trends in Santa Rosa (Santa Barbara)

The chart displays monthly precipitation patterns in Santa Rosa (Santa Barbara), 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 Santa Rosa (Santa Barbara), September typically receives around 332 mm (13.1 inches) of precipitation spread over approximately 28 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 Santa Rosa (Santa Barbara)

In Santa Rosa (Santa Barbara) in September humidity is 85%. With an average temperature of 17°C (63°F), this humidity feels like a warm, enveloping blanket that clings to your skin, making outdoor activities a bit stifling and encouraging frequent breaks in shaded areas or air-conditioned spaces for travelers.

September Average Humidity in Santa Rosa (Santa Barbara)

This chart illustrates the average monthly humidity levels in Santa Rosa (Santa Barbara), 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 Santa Rosa (Santa Barbara) is approximately 85%, 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 Santa Rosa (Santa Barbara)

In Santa Rosa (Santa Barbara) 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 Santa Rosa (Santa Barbara), you can check here.

Maximum UV Index Levels in Santa Rosa (Santa Barbara) for September

The chart shows the monthly maximum UV Index (UVI) for Santa Rosa (Santa Barbara) 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 Santa Rosa (Santa Barbara) typically reaches 14, which falls under the extreme exposure category.

Data source: Santa Rosa (Santa Barbara) 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 Santa Rosa (Santa Barbara) Compares to Other Months

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

This table compares monthly weather conditions in Santa Rosa (Santa Barbara), showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	13°C (56°F)	25 mm (1.0 inches)	70%	very high
February Weather	14°C (58°F)	34 mm (1.3 inches)	64%	extreme
March Weather	16°C (62°F)	32 mm (1.2 inches)	54%	extreme
April Weather	18°C (64°F)	17 mm (0.7 inches)	61%	extreme
May Weather	19°C (66°F)	128 mm (5.0 inches)	75%	extreme
June Weather	18°C (65°F)	288 mm (11.4 inches)	83%	extreme
July Weather	17°C (63°F)	361 mm (14.2 inches)	83%	extreme
August Weather	17°C (64°F)	383 mm (15.1 inches)	85%	extreme
September Weather	17°C (63°F)	332 mm (13.1 inches)	85%	extreme
October Weather	17°C (63°F)	199 mm (7.8 inches)	79%	extreme
November Weather	15°C (60°F)	73 mm (2.9 inches)	76%	very high
December Weather	14°C (57°F)	19 mm (0.7 inches)	74%	very high