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September Weather in San Alejo, El Salvador

Last updated: August 23, 2025

In San Alejo, El Salvador, the average temperature in September is a warm 27°C (82°F). Expect a range that can dip to a minimum of 22°C (71°F) and soar to a maximum of 38°C (100°F). This month also sees considerable precipitation, with an average of 248 mm (9.8 in) spread over 25 days. With an average humidity of 77%, it’s a great time to enjoy the heat while staying hydrated!

September Temperature in San Alejo

In September in San Alejo, the average temperature is 27°C (82°F). Maximums can reach 38°C (100°F) and minimums can be as low as 22°C (71°F). This makes it an ideal time for travelers who enjoy warm weather and outdoor activities.

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

The chart illustrates September temperature patterns in San Alejo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Alejo, September typically has an average temperature of 27°C (82°F), with highs reaching up to 38°C (100°F) and lows dropping to around 22°C (71°F).
JanFebMarAprMayJunJulAugSepOctNovDec828486868482848381808081
Data source: Temperature data for San Alejo 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 Alejo

In San Alejo in September, the precipitation amount is 248 mm (9.8 in) spread over 25 days.

September Precipitation Trends in San Alejo

The chart displays monthly precipitation patterns in San Alejo, 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 Alejo, September typically receives around 248 mm (9.8 inches) of precipitation spread over approximately 25 days.
JanFebMarAprMayJunJulAugSepOctNovDec1162924127480222248331553
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Alejo

In San Alejo in September, humidity is 77%. With an average temperature of 27°C (82°F), this humidity feels like a warm blanket wrapping around you, making travel feel heavy and slightly stifling, requiring frequent breaks and hydration to enjoy the sights comfortably.

September Average Humidity in San Alejo

This chart illustrates the average monthly humidity levels in San Alejo, 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 Alejo is approximately 77%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec63%62%59%59%59%68%78%79%77%77%75%67%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Alejo

In San Alejo 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 Alejo.

Maximum UV Index Levels in San Alejo for September

The chart shows the monthly maximum UV Index (UVI) for San Alejo 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 Alejo typically reaches 13, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec11121414141413131313109
Data source: San Alejo 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 Alejo Compares to Other Months

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

This table compares monthly weather conditions in San Alejo, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather28°C (82°F)1 mm (0.0 inches)63%extreme
February Weather29°C (84°F)1 mm (0.0 inches)62%extreme
March Weather30°C (86°F)6 mm (0.2 inches)59%extreme
April Weather30°C (86°F)29 mm (1.1 inches)59%extreme
May Weather29°C (84°F)241 mm (9.5 inches)59%extreme
June Weather28°C (82°F)274 mm (10.8 inches)68%extreme
July Weather29°C (84°F)80 mm (3.1 inches)77%extreme
August Weather28°C (83°F)222 mm (8.7 inches)79%extreme
September Weather27°C (82°F)248 mm (9.8 inches)77%extreme
October Weather27°C (80°F)331 mm (13.0 inches)77%extreme
November Weather27°C (80°F)55 mm (2.2 inches)75%very high
December Weather27°C (81°F)3 mm (0.1 inches)66%very high

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