September Weather in Rio Segundo, Costa Rica

Last updated: August 23, 2025

In Rio Segundo, Costa Rica, the average temperature in September hovers around 21°C (70°F), with minimums dipping to 16°C (61°F) and maximums reaching up to 28°C (82°F). Be prepared for frequent rain, as 287 mm (11.3 in) of precipitation falls over 29 days, contributing to an average humidity of 84%. Whether you're planning outdoor activities or seeking cozy indoor spots, this climate offers a unique experience!

September Temperature in Rio Segundo

In September in Rio Segundo, the average temperature is 21°C (70°F). The maximum can reach 28°C (82°F) and the minimum can be as low as 16°C (61°F). This pleasant climate makes Rio Segundo an ideal destination for travelers seeking comfortable weather and outdoor activities.

September Weather in Rio Segundo: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Rio Segundo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rio Segundo, September typically has an average temperature of 21°C (70°F), with highs reaching up to 28°C (82°F) and lows dropping to around 16°C (61°F).

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

September Precipitation in Rio Segundo

In Rio Segundo in September, the total precipitation amount is 287 mm (11.3 in) spread over 29 days.

September Precipitation Trends in Rio Segundo

The chart displays monthly precipitation patterns in Rio Segundo, 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 Rio Segundo, September typically receives around 287 mm (11.3 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 Rio Segundo

In Rio Segundo in September, humidity is 84%. With an average temperature of 21°C (70°F), this humidity feels like thick, warm air wrapping around you, making outdoor activities quite uncomfortable and necessitating frequent hydration breaks for a more enjoyable travel experience.

September Average Humidity in Rio Segundo

This chart illustrates the average monthly humidity levels in Rio Segundo, 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 Rio Segundo 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 Rio Segundo

In Rio Segundo 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 Rio Segundo.

Maximum UV Index Levels in Rio Segundo for September

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

Data source: Rio Segundo 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 Rio Segundo Compares to Other Months

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

This table compares monthly weather conditions in Rio Segundo, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	19°C (66°F)	109 mm (4.3 inches)	71%	extreme
February Weather	19°C (66°F)	48 mm (1.9 inches)	70%	extreme
March Weather	19°C (67°F)	57 mm (2.2 inches)	68%	extreme
April Weather	21°C (69°F)	113 mm (4.5 inches)	69%	extreme
May Weather	21°C (70°F)	310 mm (12.2 inches)	70%	extreme
June Weather	21°C (70°F)	275 mm (10.8 inches)	81%	extreme
July Weather	21°C (69°F)	275 mm (10.8 inches)	88%	extreme
August Weather	21°C (70°F)	273 mm (10.7 inches)	85%	extreme
September Weather	21°C (70°F)	287 mm (11.3 inches)	84%	extreme
October Weather	21°C (69°F)	402 mm (15.8 inches)	82%	extreme
November Weather	20°C (68°F)	272 mm (10.7 inches)	81%	extreme
December Weather	19°C (67°F)	192 mm (7.6 inches)	74%	very high