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September Weather in San Luis, Guatemala

Last updated: August 23, 2025

In September, the average temperature in San Luis, Guatemala sits at a balmy 26°C (80°F). Expect a minimum of 21°C (70°F) and a sweltering maximum of 37°C (98°F). With 199 mm (7.8 in) of precipitation spread over 26 days, it's wise to bring an umbrella. Humidity also runs high, averaging around 82%, creating a warm and tropical atmosphere.

September Temperature in San Luis

In September in San Luis, the average temperature is 26°C (80°F). Maximums can reach 37°C (98°F), and minimums can be as low as 21°C (70°F). This climate makes San Luis an ideal destination for travelers seeking warm and pleasant weather.

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

The chart illustrates September temperature patterns in San Luis, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Luis, September typically has an average temperature of 26°C (80°F), with highs reaching up to 37°C (98°F) and lows dropping to around 21°C (70°F).
JanFebMarAprMayJunJulAugSepOctNovDec727476808281808080777472
Data source: Temperature data for San Luis 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 Luis

In San Luis in September, the total precipitation amount is 199 mm (7.8 in) spread over 26 days.

September Precipitation Trends in San Luis

The chart displays monthly precipitation patterns in San Luis, 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 Luis, September typically receives around 199 mm (7.8 inches) of precipitation spread over approximately 26 days.
JanFebMarAprMayJunJulAugSepOctNovDec7045555413120411513819926717982
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Luis

In San Luis in September, humidity is 82%. With an average temperature of 26°C (80°F), this humidity feels like a heavy, warm blanket wrapping around you, making outdoor activities feel more exhausting and sweaty, which can be quite challenging for traveling.

September Average Humidity in San Luis

This chart illustrates the average monthly humidity levels in San Luis, 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 Luis is approximately 82%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%78%67%62%62%63%66%73%82%86%87%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Luis

In San Luis 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 San Luis.

Maximum UV Index Levels in San Luis for September

The chart shows the monthly maximum UV Index (UVI) for San Luis 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 Luis typically reaches 13, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec10121314141313131312109
Data source: San Luis 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 Luis Compares to Other Months

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

This table compares monthly weather conditions in San Luis, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather22°C (72°F)70 mm (2.8 inches)85%very high
February Weather23°C (74°F)45 mm (1.8 inches)78%extreme
March Weather24°C (76°F)55 mm (2.2 inches)67%extreme
April Weather27°C (81°F)54 mm (2.1 inches)62%extreme
May Weather28°C (82°F)131 mm (5.2 inches)62%extreme
June Weather27°C (81°F)204 mm (8.0 inches)63%extreme
July Weather27°C (80°F)115 mm (4.5 inches)66%extreme
August Weather27°C (80°F)138 mm (5.4 inches)73%extreme
September Weather26°C (80°F)199 mm (7.8 inches)82%extreme
October Weather25°C (78°F)267 mm (10.5 inches)86%extreme
November Weather23°C (74°F)179 mm (7.1 inches)87%very high
December Weather22°C (72°F)82 mm (3.2 inches)87%very high

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