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September Weather in San Francisco, Bolivia

Last updated: August 22, 2025

In San Francisco, Bolivia, the average temperature in September is a pleasant 14°C (57°F). You can expect a minimum of 0°C (33°F) and a comfortable maximum of 29°C (85°F). Be prepared for some rain, as the area sees about 53 mm (2.1 in) of precipitation spread over 12 days. Don't forget to consider the average humidity, which sits at 42%, adding a touch of moisture to the air.

September Temperature in San Francisco

In September in San Francisco, the average temperature is 14°C (57°F), with maximums reaching up to 29°C (85°F) and minimums dropping as low as 0°C (33°F). It's advisable to pack layers for your travel, as the weather can vary significantly throughout the day.

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 14°C (57°F), with highs reaching up to 29°C (85°F) and lows dropping to around 0°C (33°F).
JanFebMarAprMayJunJulAugSepOctNovDec616059575451505256596060
Data source: Temperature data for San Francisco 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 Francisco

In San Francisco in September, the total precipitation amount is 53 mm (2.1 in) spread over 12 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 53 mm (2.1 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec174225185112442124235390126249
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Francisco

In San Francisco in September humidity is 42%. With average temperature 14°C (57°F), this humidity feels like a mild and refreshing breeze, making it pleasant for exploring the area without feeling overly 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 42%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%81%78%82%82%69%49%33%42%49%78%87%
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 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 Francisco, you can check here.

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 14, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec1717161411891214171818
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 Weather16°C (61°F)174 mm (6.8 inches)87%extreme
February Weather15°C (60°F)225 mm (8.9 inches)81%extreme
March Weather15°C (59°F)185 mm (7.3 inches)78%extreme
April Weather14°C (57°F)112 mm (4.4 inches)82%extreme
May Weather12°C (54°F)43 mm (1.7 inches)82%extreme
June Weather11°C (52°F)21 mm (0.8 inches)69%very high
July Weather10°C (51°F)24 mm (0.9 inches)49%very high
August Weather11°C (52°F)23 mm (0.9 inches)33%extreme
September Weather14°C (57°F)53 mm (2.1 inches)42%extreme
October Weather15°C (60°F)90 mm (3.5 inches)49%extreme
November Weather16°C (60°F)126 mm (4.9 inches)78%extreme
December Weather16°C (60°F)249 mm (9.8 inches)87%extreme

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