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September Weather in San Clemente, Mexico

Last updated: August 26, 2025

In September, the average temperature in San Clemente, Mexico hovers around 21°C (71°F), making it a pleasant time to visit. Expect temperatures to range from a minimum of 12°C (55°F) to a maximum of 30°C (86°F). However, be prepared for some rain, as the area typically sees about 235 mm (9.2 in) of precipitation over 25 days. With an average humidity level of 84%, it's advisable to dress in layers to stay comfortable.

September Temperature in San Clemente

In September in San Clemente, the average temperature is 21°C (71°F), with maximums reaching up to 30°C (86°F) and minimums dropping as low as 12°C (55°F). This pleasant climate makes San Clemente an ideal destination for travelers seeking a comfortable getaway.

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 (71°F), with highs reaching up to 30°C (86°F) and lows dropping to around 12°C (55°F).
JanFebMarAprMayJunJulAugSepOctNovDec586165697272717171686359
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 235 mm (9.2 in) spread over 25 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 235 mm (9.2 inches) of precipitation spread over approximately 25 days.
JanFebMarAprMayJunJulAugSepOctNovDec6859839316021915820923526710347
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 84%. With an average temperature of 21°C (71°F), this humidity feels like a warm, muggy embrace that can leave travelers feeling sticky and sluggish, making outdoor adventures a bit more challenging but also invigorating in the right moments.

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 84%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec89%86%83%80%82%79%72%74%84%92%91%91%
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 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 Clemente.

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 13, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec811131414141414131298
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 Weather15°C (59°F)68 mm (2.7 inches)88%very high
February Weather16°C (62°F)59 mm (2.3 inches)86%extreme
March Weather18°C (65°F)83 mm (3.3 inches)83%extreme
April Weather21°C (69°F)93 mm (3.7 inches)80%extreme
May Weather22°C (73°F)160 mm (6.3 inches)82%extreme
June Weather22°C (72°F)219 mm (8.6 inches)79%extreme
July Weather22°C (71°F)158 mm (6.2 inches)72%extreme
August Weather22°C (72°F)209 mm (8.2 inches)74%extreme
September Weather21°C (71°F)235 mm (9.2 inches)84%extreme
October Weather20°C (68°F)267 mm (10.5 inches)92%extreme
November Weather17°C (63°F)102 mm (4.0 inches)91%very high
December Weather15°C (60°F)47 mm (1.9 inches)91%very high

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