September Weather in Belen, Costa Rica

Last updated: August 23, 2025

In September, the average temperature in Belen, Costa Rica hovers around 26°C (79°F). Expect a mild minimum of 21°C (71°F) and a warm maximum of 34°C (93°F). However, be prepared for frequent rainfall, as the area experiences about 277 mm (10.9 in) of precipitation spread over 27 days. With an average humidity of 80%, the air can feel quite muggy, making it a unique experience for visitors!

September Temperature in Belen

In September, in Belen, the average temperature is 26°C (79°F). The maximum can reach 34°C (93°F) and the minimum can be as low as 21°C (71°F). This pleasant weather makes Belen an ideal destination for travelers seeking warmth and comfort.

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

The chart illustrates September temperature patterns in Belen, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Belen, September typically has an average temperature of 26°C (79°F), with highs reaching up to 34°C (93°F) and lows dropping to around 21°C (71°F).

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

September Precipitation in Belen

In Belen in September, the precipitation amount is 277 mm (10.9 in) spread over 27 days, indicating a frequent but varied pattern of rainfall throughout the month.

September Precipitation Trends in Belen

The chart displays monthly precipitation patterns in Belen, 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 Belen, September typically receives around 277 mm (10.9 inches) of precipitation spread over approximately 27 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 Belen

In Belen in September humidity is 80%. With an average temperature of 26°C (79°F), this humidity feels like a heavy blanket, making outdoor activities feel sticky and exhausting, potentially dampening the travel experience and necessitating frequent breaks to cool down and hydrate.

September Average Humidity in Belen

This chart illustrates the average monthly humidity levels in Belen, 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 Belen is approximately 80%, 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 Belen

In Belen 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 Belen.

Maximum UV Index Levels in Belen for September

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

Data source: Belen 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 Belen Compares to Other Months

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

This table compares monthly weather conditions in Belen, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	27°C (81°F)	5 mm (0.2 inches)	66%	extreme
February Weather	28°C (82°F)	1 mm (0.0 inches)	64%	extreme
March Weather	28°C (83°F)	1 mm (0.0 inches)	63%	extreme
April Weather	29°C (85°F)	35 mm (1.4 inches)	63%	extreme
May Weather	28°C (82°F)	255 mm (10.1 inches)	63%	extreme
June Weather	27°C (81°F)	289 mm (11.4 inches)	74%	extreme
July Weather	27°C (81°F)	115 mm (4.5 inches)	85%	extreme
August Weather	27°C (81°F)	224 mm (8.8 inches)	82%	extreme
September Weather	26°C (79°F)	277 mm (10.9 inches)	80%	extreme
October Weather	26°C (79°F)	374 mm (14.7 inches)	79%	extreme
November Weather	26°C (79°F)	138 mm (5.4 inches)	79%	extreme
December Weather	27°C (80°F)	12 mm (0.5 inches)	70%	very high