September Weather in Mejillones, Chile

Last updated: August 22, 2025

In September, the average temperature in Mejillones, Chile hovers around 15°C (59°F), offering a comfortable climate for outdoor activities. Expect a minimum of 11°C (52°F) and a maximum of 18°C (65°F), providing a pleasant range for your adventures. Precipitation is typically light, with around 10 mm (0.4 in) falling over just 1 day. With an average humidity of 77%, the air may feel a bit brisk, so be sure to dress accordingly!

September Temperature in Mejillones

In September in Mejillones, the average temperature is 15°C (59°F). Maximums can reach 18°C (65°F), while minimums can drop as low as 11°C (52°F). This climate makes Mejillones a comfortable destination for travelers looking to enjoy mild weather.

September Weather in Mejillones: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Mejillones, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Mejillones, September typically has an average temperature of 15°C (59°F), with highs reaching up to 18°C (65°F) and lows dropping to around 11°C (52°F).

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

September Precipitation in Mejillones

In Mejillones in September, the precipitation amount is 10 mm (0.4 in) over the course of 1 day.

September Precipitation Trends in Mejillones

The chart displays monthly precipitation patterns in Mejillones, 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 Mejillones, September typically receives around 10 mm (0.4 inches) of precipitation spread over approximately 1 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Mejillones

In Mejillones in September, humidity is 77%. With an average temperature of 15°C (59°F), this humidity feels like a warm blanket enveloping you, making it essential to stay hydrated and choose light, breathable clothing for comfortable travel.

September Average Humidity in Mejillones

This chart illustrates the average monthly humidity levels in Mejillones, 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 Mejillones is approximately 77%, 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 Mejillones

In Mejillones 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 Mejillones.

Maximum UV Index Levels in Mejillones for September

The chart shows the monthly maximum UV Index (UVI) for Mejillones 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 Mejillones typically reaches 11, which falls under the extreme exposure category.

Data source: Mejillones 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 Mejillones Compares to Other Months

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

This table compares monthly weather conditions in Mejillones, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	20°C (69°F)	4 mm (0.1 inches)	83%	extreme
February Weather	21°C (69°F)	1 mm (0.1 inches)	84%	extreme
March Weather	20°C (68°F)	3 mm (0.1 inches)	84%	extreme
April Weather	18°C (65°F)	7 mm (0.3 inches)	83%	very high
May Weather	17°C (62°F)	10 mm (0.4 inches)	80%	very high
June Weather	16°C (60°F)	13 mm (0.5 inches)	79%	high
July Weather	15°C (59°F)	14 mm (0.5 inches)	77%	high
August Weather	15°C (59°F)	11 mm (0.4 inches)	75%	very high
September Weather	15°C (59°F)	10 mm (0.4 inches)	77%	extreme
October Weather	15°C (60°F)	8 mm (0.3 inches)	77%	extreme
November Weather	17°C (63°F)	6 mm (0.3 inches)	79%	extreme
December Weather	19°C (66°F)	5 mm (0.2 inches)	78%	extreme