September Weather in Arenal, Colombia

Last updated: August 23, 2025

In Arenal, Colombia, the weather in September features an average temperature of 27°C (82°F). Expect minimums around 22°C (73°F) and maximums rising to 36°C (97°F). With an average humidity of 83% and about 193 mm (7.6 in) of precipitation spread over 25 days, be prepared for a humid, rainy month!

September Temperature in Arenal

In September in Arenal, the average temperature is 27°C (82°F), with maximums reaching 36°C (97°F) and minimums dropping as low as 22°C (73°F). This makes it a comfortable time to travel, perfect for enjoying outdoor activities and exploring the local attractions.

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

The chart illustrates September temperature patterns in Arenal, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Arenal, September typically has an average temperature of 27°C (82°F), with highs reaching up to 36°C (97°F) and lows dropping to around 22°C (73°F).

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

September Precipitation in Arenal

In Arenal in September, the precipitation amount is 193 mm (7.6 in) over the course of 25 days.

September Precipitation Trends in Arenal

The chart displays monthly precipitation patterns in Arenal, 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 Arenal, September typically receives around 193 mm (7.6 inches) of precipitation spread over approximately 25 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 Arenal

In Arenal in September humidity is 83%. With an average temperature of 27°C (82°F), this humidity feels like a thick, warm blanket enveloping you, making outdoor activities exhausting and encouraging visitors to seek the comfort of shade or air conditioning while exploring the area.

September Average Humidity in Arenal

This chart illustrates the average monthly humidity levels in Arenal, 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 Arenal is approximately 83%, 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 Arenal

In Arenal 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 Arenal.

Maximum UV Index Levels in Arenal for September

The chart shows the monthly maximum UV Index (UVI) for Arenal 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 Arenal typically reaches 13, which falls under the extreme exposure category.

Data source: Arenal 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 Arenal Compares to Other Months

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

This table compares monthly weather conditions in Arenal, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	28°C (84°F)	22 mm (0.9 inches)	51%	extreme
February Weather	30°C (86°F)	5 mm (0.2 inches)	47%	extreme
March Weather	30°C (86°F)	54 mm (2.1 inches)	45%	extreme
April Weather	28°C (83°F)	171 mm (6.7 inches)	46%	extreme
May Weather	28°C (82°F)	272 mm (10.7 inches)	62%	extreme
June Weather	28°C (82°F)	192 mm (7.6 inches)	81%	extreme
July Weather	28°C (83°F)	136 mm (5.3 inches)	87%	extreme
August Weather	28°C (83°F)	187 mm (7.4 inches)	83%	extreme
September Weather	27°C (82°F)	193 mm (7.6 inches)	83%	extreme
October Weather	27°C (81°F)	205 mm (8.1 inches)	85%	extreme
November Weather	27°C (81°F)	181 mm (7.1 inches)	83%	extreme
December Weather	28°C (82°F)	39 mm (1.5 inches)	65%	very high