nomadseason

September Weather in Santiago, Mexico

Last updated: August 27, 2025

In September, the average temperature in Santiago, Mexico hovers around 22°C (71°F). You can expect a minimum of 13°C (56°F) and a maximum of 31°C (89°F). Precipitation is relatively high, with an average of 191 mm (7.5 in) spread over 18 days. Additionally, the air is quite humid, with an average humidity level of 72%.

September Temperature in Santiago

In September in Santiago, the average temperature is 22°C (71°F). The maximum can reach 31°C (89°F) and the minimum can be as low as 13°C (56°F). This pleasant climate makes Santiago an ideal destination for travelers seeking comfortable weather and outdoor activities.

September Weather in Santiago: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Santiago, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santiago, September typically has an average temperature of 22°C (71°F), with highs reaching up to 31°C (89°F) and lows dropping to around 13°C (56°F).
JanFebMarAprMayJunJulAugSepOctNovDec525662667173747571665955
Data source: Temperature data for Santiago generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Santiago

In Santiago in September, the total precipitation amount is 191 mm (7.5 in), occurring over a span of 18 days.

September Precipitation Trends in Santiago

The chart displays monthly precipitation patterns in Santiago, 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 Santiago, September typically receives around 191 mm (7.5 inches) of precipitation spread over approximately 18 days.
JanFebMarAprMayJunJulAugSepOctNovDec4678981871939312031191735450
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Santiago

In Santiago in September humidity is 72%. With an average temperature of 22°C (71°F), this humidity feels like a warm embrace, making outdoor activities enjoyable but potentially sticky, urging travelers to stay hydrated and take breaks in the shade.

September Average Humidity in Santiago

This chart illustrates the average monthly humidity levels in Santiago, 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 Santiago is approximately 72%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec75%70%65%59%66%71%57%58%73%76%81%80%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Santiago

In Santiago in September, the maximum UV index is 12, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, underscoring the importance of sun protection. For detailed information, you can check the Hourly UV Index in Santiago.

Maximum UV Index Levels in Santiago for September

The chart shows the monthly maximum UV Index (UVI) for Santiago 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 Santiago typically reaches 12, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec79111313131312121186
Data source: Santiago 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 Santiago Compares to Other Months

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

This table compares monthly weather conditions in Santiago, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather11°C (53°F)45 mm (1.8 inches)75%high
February Weather14°C (57°F)78 mm (3.1 inches)70%very high
March Weather17°C (62°F)98 mm (3.9 inches)65%extreme
April Weather19°C (67°F)187 mm (7.4 inches)59%extreme
May Weather22°C (72°F)193 mm (7.6 inches)66%extreme
June Weather23°C (74°F)93 mm (3.7 inches)71%extreme
July Weather23°C (74°F)120 mm (4.7 inches)57%extreme
August Weather24°C (75°F)30 mm (1.2 inches)58%extreme
September Weather22°C (71°F)191 mm (7.5 inches)72%extreme
October Weather19°C (66°F)73 mm (2.9 inches)76%extreme
November Weather15°C (59°F)54 mm (2.1 inches)81%very high
December Weather13°C (55°F)50 mm (2.0 inches)80%high

Compare Santiago's Climate with Cities Worldwide