nomadseason

September Weather in Monterey, United States

Last updated: June 24, 2025

In Monterey, United States, the average temperature in September hovers around 17°C (64°F). Expect a minimum of 1°C (34°F) and a maximum of 29°C (85°F), providing a wide range of weather experiences. During this month, you can anticipate 117 mm (4.6 in) of precipitation spread over about 12 days, resulting in an average humidity of 68%. Whether you're planning outdoor activities or cozy indoor time, be prepared for a mix of conditions!

September Temperature in Monterey

In September in Monterey, the average temperature is 17°C (64°F). Maximum temperatures can reach 29°C (85°F), while minimum temperatures can dip as low as 1°C (34°F). Be sure to pack layers to accommodate the wide range of temperatures during your trip!

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

The chart illustrates September temperature patterns in Monterey, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Monterey, September typically has an average temperature of 17°C (64°F), with highs reaching up to 29°C (85°F) and lows dropping to around 1°C (34°F).
JanFebMarAprMayJunJulAugSepOctNovDec303640505966706863544035
Data source: Temperature data for Monterey 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 Monterey

In Monterey in September, the total precipitation amount is 117 mm (4.6 in), occurring over a span of 12 days.

September Precipitation Trends in Monterey

The chart displays monthly precipitation patterns in Monterey, 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 Monterey, September typically receives around 117 mm (4.6 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec7611586126151107861291171167296
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Monterey

In Monterey in September, humidity is 68%. With an average temperature of 17°C (64°F), this humidity feels like a damp embrace that lingers on the skin, making every step feel heavier and every breath a little more labored, which can be a challenge for traveling.

September Average Humidity in Monterey

This chart illustrates the average monthly humidity levels in Monterey, 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 Monterey is approximately 68%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%86%86%84%78%79%70%59%68%80%87%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Monterey

In Monterey 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 Monterey.

Maximum UV Index Levels in Monterey for September

The chart shows the monthly maximum UV Index (UVI) for Monterey 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 Monterey typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec36810111111109753
Data source: Monterey 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 Monterey Compares to Other Months

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

This table compares monthly weather conditions in Monterey, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-1°C (31°F)76 mm (3.0 inches)86%moderate
February Weather2°C (36°F)115 mm (4.5 inches)86%high
March Weather5°C (41°F)86 mm (3.4 inches)86%very high
April Weather10°C (50°F)126 mm (5.0 inches)84%very high
May Weather15°C (60°F)151 mm (5.9 inches)78%extreme
June Weather19°C (66°F)107 mm (4.2 inches)79%extreme
July Weather21°C (70°F)86 mm (3.4 inches)70%extreme
August Weather20°C (68°F)129 mm (5.1 inches)59%very high
September Weather17°C (64°F)117 mm (4.6 inches)68%very high
October Weather12°C (54°F)115 mm (4.5 inches)80%high
November Weather4°C (40°F)72 mm (2.8 inches)86%moderate
December Weather2°C (35°F)96 mm (3.8 inches)85%moderate

Compare Monterey's Climate with Cities Worldwide