Half Moon Bay
California, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Half Moon Bay, CA

A warm and sunny day on a scenic beach in Half Moon Bay, California
A warm and sunny day on a scenic beach in Half Moon Bay, California
September, the first month of the autumn, in Half Moon Bay, is still a comfortable month, with average temperature ranging between min 51.3°F (10.7°C) and max 66.7°F (19.3°C).

Temperature

With an average high-temperature of 66.7°F (19.3°C) and an average low-temperature of 51.3°F (10.7°C), September is the warmest month.

Rainfall

In Half Moon Bay, California, in September, it is raining for 4 days, with typically 0.4" (8.9mm) of accumulated precipitation. Throughout the year, in Half Moon Bay, there are 87 rainfall days, and 26.2" (664.6mm) of precipitation is accumulated.

Daylight

In September, the average length of the day in Half Moon Bay is 12.4h.

What is the warmest month in Half Moon Bay?

With an average high-temperature of 66.7°F (19.3°C) and an average low-temperature of 51.3°F (10.7°C), September is the warmest month in Half Moon Bay.

What is the temperature in September in Half Moon Bay?

The average high-temperature, in September, in Half Moon Bay, California, is 66.7°F (19.3°C), while the average low-temperature is 51.3°F (10.7°C).

How much does it rain in Half Moon Bay in September?

In Half Moon Bay, California, in September, it is raining for 4 days, with typically 0.4" (8.9mm) of accumulated precipitation.

What is the average length of the day in September in Half Moon Bay?

In Half Moon Bay, California, the average length of the day in September is 12.4h.
Average temperature in September - Half Moon Bay, CA
  • Average high temperature in September: 66.8°F

The warmest month (with the highest average high temperature) is September (66.8°F).
The month with the lowest average high temperature is January (58.4°F).

  • Average low temperature in September: 51.2°F

The month with the highest average low temperature is August (52.7°F).
The coldest month (with the lowest average low temperature) is January (42.9°F).

Average rainfall in September - Half Moon Bay, CA
  • Average rainfall in September: 0.4"

The wettest month (with the highest rainfall) is January (5.2").
The driest month (with the lowest rainfall) is July (0.1").

Average rainfall days in September - Half Moon Bay, CA
  • Average rainfall days in September: 4 days

The month with the highest number of rainy days is January (12 days).
The month with the lowest number of rainy days is June (3 days).

Average daylight in September - Half Moon Bay, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.7h).
The month with shortest days is December (Average daylight: 9.6h).