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September Weather in San Juan, Panama

Last updated: August 27, 2025

In San Juan, Panama, the average temperature in September is a pleasant 25°C (78°F). Expect a minimum of 21°C (70°F) and a maximum of 32°C (91°F). During this period, precipitation reaches 459 mm (18.1 in) over 30 days, while the average humidity sits at a notable 87%. Stay prepared for a month of warmth and moisture!

September Temperature in San Juan

In September in San Juan, the average temperature is 25°C (78°F). Maximum can reach 32°C (91°F) and minimum can be as low as 21°C (70°F). This makes it an ideal time for travelers to enjoy outdoor activities while experiencing comfortable weather.

September Weather in San Juan: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in San Juan, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Juan, September typically has an average temperature of 25°C (78°F), with highs reaching up to 32°C (91°F) and lows dropping to around 21°C (70°F).
JanFebMarAprMayJunJulAugSepOctNovDec798081817978787877777778
Data source: Temperature data for San Juan generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in San Juan

In San Juan in September, the precipitation amount is 459 mm (18.1 in) over the course of 30 days.

September Precipitation Trends in San Juan

The chart displays monthly precipitation patterns in San Juan, 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 San Juan, September typically receives around 459 mm (18.1 inches) of precipitation spread over approximately 30 days.
JanFebMarAprMayJunJulAugSepOctNovDec3187105355353404359459411385103
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Juan

In San Juan in September, humidity is 87%. With an average temperature of 25°C (78°F), this humidity feels like a warm, heavy blanket enveloping you, making outdoor activities particularly strenuous and requiring frequent breaks for hydration and shade.

September Average Humidity in San Juan

This chart illustrates the average monthly humidity levels in San Juan, 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 San Juan is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec72%71%69%70%73%90%89%87%87%86%86%79%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Juan

In San Juan 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 San Juan, you can check here.

Maximum UV Index Levels in San Juan for September

The chart shows the monthly maximum UV Index (UVI) for San Juan 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 San Juan typically reaches 14, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec121314151513141314141211
Data source: San Juan 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 San Juan Compares to Other Months

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

This table compares monthly weather conditions in San Juan, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather26°C (79°F)31 mm (1.2 inches)72%extreme
February Weather27°C (80°F)8 mm (0.3 inches)71%extreme
March Weather27°C (81°F)7 mm (0.3 inches)69%extreme
April Weather27°C (81°F)105 mm (4.1 inches)70%extreme
May Weather26°C (79°F)355 mm (14.0 inches)73%extreme
June Weather26°C (78°F)353 mm (13.9 inches)90%extreme
July Weather26°C (78°F)404 mm (15.9 inches)88%extreme
August Weather25°C (78°F)359 mm (14.1 inches)87%extreme
September Weather25°C (78°F)459 mm (18.1 inches)87%extreme
October Weather25°C (77°F)410 mm (16.2 inches)86%extreme
November Weather25°C (77°F)385 mm (15.1 inches)86%extreme
December Weather26°C (78°F)103 mm (4.1 inches)79%extreme

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