nomadseason

September Weather in San Francisco, Colombia

Last updated: August 23, 2025

In San Francisco, Colombia, the average temperature in September hovers around 13°C (55°F), with a minimum of 6°C (43°F) and a maximum reaching 22°C (71°F). Expect 186 mm (7.3 in) of precipitation distributed across 21 days, resulting in an average humidity of 53%. Plan your activities accordingly and make the most of the mild weather!

September Temperature in San Francisco

In September in San Francisco, the average temperature is 13°C (55°F). Maximum temperatures can reach 22°C (71°F), while minimums can drop as low as 6°C (43°F). This mild climate makes San Francisco an ideal destination for outdoor activities and exploration during this time of year.

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

The chart illustrates September temperature patterns in San Francisco, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Francisco, September typically has an average temperature of 13°C (55°F), with highs reaching up to 22°C (71°F) and lows dropping to around 6°C (43°F).
JanFebMarAprMayJunJulAugSepOctNovDec565756565655545455565756
Data source: Temperature data for San Francisco 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 San Francisco

In San Francisco in September, the precipitation amount is 186 mm (7.3 in) during a span of 21 days.

September Precipitation Trends in San Francisco

The chart displays monthly precipitation patterns in San Francisco, 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 Francisco, September typically receives around 186 mm (7.3 inches) of precipitation spread over approximately 21 days.
JanFebMarAprMayJunJulAugSepOctNovDec205218350336353292231161186274306272
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in San Francisco

In San Francisco in September humidity is 53%. With an average temperature of 13°C (55°F), this humidity feels like a crisp morning breeze, making it perfect for exploring the sights without feeling too hot or sticky.

September Average Humidity in San Francisco

This chart illustrates the average monthly humidity levels in San Francisco, 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 Francisco is approximately 53%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec72%66%74%83%93%93%84%61%53%67%78%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Francisco

In San Francisco in September, the maximum UV index is 16, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, making it crucial to take protective measures. For detailed information, you can refer to the Hourly UV Index in San Francisco.

Maximum UV Index Levels in San Francisco for September

The chart shows the monthly maximum UV Index (UVI) for San Francisco 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 Francisco typically reaches 16, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec171719191714151516171513
Data source: San Francisco 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 Francisco Compares to Other Months

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

This table compares monthly weather conditions in San Francisco, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather13°C (56°F)205 mm (8.1 inches)72%extreme
February Weather14°C (57°F)218 mm (8.6 inches)66%extreme
March Weather14°C (57°F)350 mm (13.8 inches)74%extreme
April Weather13°C (56°F)336 mm (13.2 inches)83%extreme
May Weather13°C (56°F)353 mm (13.9 inches)93%extreme
June Weather13°C (55°F)292 mm (11.5 inches)93%extreme
July Weather12°C (54°F)231 mm (9.1 inches)84%extreme
August Weather12°C (54°F)161 mm (6.3 inches)61%extreme
September Weather13°C (55°F)186 mm (7.3 inches)53%extreme
October Weather13°C (56°F)274 mm (10.8 inches)67%extreme
November Weather14°C (57°F)305 mm (12.0 inches)78%extreme
December Weather13°C (56°F)272 mm (10.7 inches)85%extreme

Compare San Francisco's Climate with Cities Worldwide