September Weather in San Francisco, Philippines

Last updated: August 27, 2025

In San Francisco, Philippines, the average temperature in September hovers around 28°C (82°F), with minimums dipping to 25°C (77°F) and maximums reaching 29°C (85°F). Expect some wet days, as precipitation totals 215 mm (8.5 in) over a span of 24 days, contributing to a high average humidity of 84%. Enjoy the tropical ambiance, but don't forget your umbrella!

September Temperature in San Francisco

In September in San Francisco, the average temperature is 28°C (82°F). The maximum can reach 29°C (85°F), while the minimum can be as low as 25°C (77°F). This pleasant weather makes it an ideal time for travelers to explore and enjoy all the outdoor activities that San Francisco has to offer.

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 28°C (82°F), with highs reaching up to 29°C (85°F) and lows dropping to around 25°C (77°F).

Data source: Temperature data for San Francisco generated using information from the Copernicus Climate Change Service.

September Precipitation in San Francisco

In San Francisco in September, the total precipitation amount is 215 mm (8.5 in) spread out over 24 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 215 mm (8.5 inches) of precipitation spread over approximately 24 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in San Francisco

In San Francisco in September humidity is 84%. With an average temperature of 28°C (82°F), this humidity feels like a warm, thick blanket wrapping around you, making outdoor activities feel sticky and exhausting for traveling.

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 84%, offering insight into how humid the weather typically is during this month.

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.

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.
	Temperature	Precipitation	Humidity	UV
January Weather	26°C (79°F)	297 mm (11.7 inches)	90%	extreme
February Weather	26°C (79°F)	224 mm (8.8 inches)	90%	extreme
March Weather	26°C (80°F)	162 mm (6.4 inches)	90%	extreme
April Weather	27°C (81°F)	90 mm (3.6 inches)	88%	extreme
May Weather	27°C (82°F)	132 mm (5.2 inches)	83%	extreme
June Weather	28°C (82°F)	186 mm (7.3 inches)	81%	extreme
July Weather	28°C (82°F)	238 mm (9.4 inches)	80%	extreme
August Weather	28°C (82°F)	189 mm (7.4 inches)	81%	extreme
September Weather	28°C (82°F)	215 mm (8.5 inches)	84%	extreme
October Weather	27°C (81°F)	263 mm (10.4 inches)	81%	extreme
November Weather	27°C (81°F)	241 mm (9.5 inches)	84%	extreme
December Weather	27°C (80°F)	391 mm (15.4 inches)	88%	extreme