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September Weather in San Clemente, Mexico

Last updated: August 27, 2025

In San Clemente, Mexico, the average temperature in September hovers around 21°C (70°F), with a minimum of 16°C (60°F) and a maximum of 31°C (89°F). Expect a precipitation total of 220 mm (8.7 in) spread over 24 days, contributing to an average humidity of 83%. Stay prepared for a humid and refreshing month!

September Temperature in San Clemente

In September in San Clemente, the average temperature is 21°C (70°F). Maximum can reach 31°C (89°F), and minimum can be as low as 16°C (60°F). This pleasant weather makes it an ideal time for outdoor activities and exploring the area.

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

The chart illustrates September temperature patterns in San Clemente, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Clemente, September typically has an average temperature of 21°C (70°F), with highs reaching up to 31°C (89°F) and lows dropping to around 16°C (60°F).
JanFebMarAprMayJunJulAugSepOctNovDec636569717372707070706764
Data source: Temperature data for San Clemente 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 Clemente

In San Clemente in September, the total precipitation amount is 220 mm (8.7 in) spread over a duration of 24 days.

September Precipitation Trends in San Clemente

The chart displays monthly precipitation patterns in San Clemente, 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 Clemente, September typically receives around 220 mm (8.7 inches) of precipitation spread over approximately 24 days.
JanFebMarAprMayJunJulAugSepOctNovDec132632291611782212201012416
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Clemente

In San Clemente in September humidity is 83%. With an average temperature of 21°C (70°F), this humidity feels like you’re enveloped in a warm, tropical embrace, making it essential to stay hydrated and take breaks during your travels.

September Average Humidity in San Clemente

This chart illustrates the average monthly humidity levels in San Clemente, 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 Clemente is approximately 83%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec70%65%59%60%67%80%81%83%83%80%77%76%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Clemente

In San Clemente 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 Clemente, you can check here.

Maximum UV Index Levels in San Clemente for September

The chart shows the monthly maximum UV Index (UVI) for San Clemente 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 Clemente typically reaches 14, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec9111414141413131412108
Data source: San Clemente 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 Clemente Compares to Other Months

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

This table compares monthly weather conditions in San Clemente, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather17°C (64°F)13 mm (0.5 inches)70%very high
February Weather18°C (65°F)26 mm (1.0 inches)65%extreme
March Weather20°C (69°F)3 mm (0.1 inches)59%extreme
April Weather22°C (71°F)2 mm (0.1 inches)60%extreme
May Weather23°C (73°F)29 mm (1.1 inches)67%extreme
June Weather22°C (73°F)161 mm (6.3 inches)80%extreme
July Weather21°C (71°F)178 mm (7.0 inches)81%extreme
August Weather21°C (71°F)221 mm (8.7 inches)83%extreme
September Weather21°C (70°F)220 mm (8.7 inches)83%extreme
October Weather21°C (70°F)101 mm (4.0 inches)80%extreme
November Weather20°C (68°F)24 mm (1.0 inches)77%very high
December Weather18°C (64°F)16 mm (0.6 inches)76%very high

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