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September Weather in Tamalpais-Homestead Valley, United States

Last updated: June 24, 2025

In September, the average temperature in Tamalpais-Homestead Valley, United States hovers around 18°C (65°F), with a minimum dipping to 9°C (49°F) and a peak of 36°C (98°F). You'll experience minimal precipitation, with only about 2 mm (0.1 in) falling over the course of 0 days. Notably, the air remains quite humid, averaging 86% humidity throughout the month.

September Temperature in Tamalpais-Homestead Valley

In September in Tamalpais-Homestead Valley, the average temperature is 18°C (65°F). The maximum can reach 36°C (98°F) and the minimum can be as low as 9°C (49°F). This makes it an ideal time for travelers looking to experience mild weather while enjoying various outdoor activities.

September Weather in Tamalpais-Homestead Valley: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Tamalpais-Homestead Valley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Tamalpais-Homestead Valley, September typically has an average temperature of 18°C (65°F), with highs reaching up to 36°C (98°F) and lows dropping to around 9°C (49°F).
JanFebMarAprMayJunJulAugSepOctNovDec515253575963636465625551
Data source: Temperature data for Tamalpais-Homestead Valley 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 Tamalpais-Homestead Valley

In Tamalpais-Homestead Valley in September, the precipitation amount is 2 mm (0.1 in) during a span of 0 days.

September Precipitation Trends in Tamalpais-Homestead Valley

The chart displays monthly precipitation patterns in Tamalpais-Homestead Valley, 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 Tamalpais-Homestead Valley, September typically receives around 2 mm (0.1 inches) of precipitation spread over approximately 0 days.
JanFebMarAprMayJunJulAugSepOctNovDec1111168035202212304898
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Tamalpais-Homestead Valley

In Tamalpais-Homestead Valley in September humidity is 86%. With an average temperature of 18°C (65°F), this humidity feels like you’re wrapped in a warm, heavy blanket, making outdoor activities feel quite muggy and sticky for traveling.

September Average Humidity in Tamalpais-Homestead Valley

This chart illustrates the average monthly humidity levels in Tamalpais-Homestead Valley, 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 Tamalpais-Homestead Valley is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%82%82%79%83%84%87%87%86%80%79%79%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Tamalpais-Homestead Valley

In Tamalpais-Homestead Valley in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Tamalpais-Homestead Valley.

Maximum UV Index Levels in Tamalpais-Homestead Valley for September

The chart shows the monthly maximum UV Index (UVI) for Tamalpais-Homestead Valley 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 Tamalpais-Homestead Valley typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3589101111109643
Data source: Tamalpais-Homestead Valley 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 Tamalpais-Homestead Valley Compares to Other Months

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

This table compares monthly weather conditions in Tamalpais-Homestead Valley, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather10°C (51°F)111 mm (4.4 inches)85%moderate
February Weather11°C (52°F)116 mm (4.6 inches)82%moderate
March Weather12°C (54°F)80 mm (3.1 inches)82%very high
April Weather14°C (57°F)35 mm (1.4 inches)79%very high
May Weather15°C (60°F)20 mm (0.8 inches)83%very high
June Weather17°C (63°F)2 mm (0.1 inches)84%extreme
July Weather17°C (63°F)2 mm (0.1 inches)87%extreme
August Weather18°C (64°F)1 mm (0.1 inches)87%very high
September Weather18°C (65°F)2 mm (0.1 inches)86%very high
October Weather16°C (62°F)30 mm (1.2 inches)80%high
November Weather13°C (55°F)48 mm (1.9 inches)79%moderate
December Weather10°C (51°F)98 mm (3.9 inches)79%moderate

Compare Tamalpais-Homestead Valley's Climate with Cities Worldwide