Santa Monica
California, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Santa Monica, CA

A night view of the neon-lit fun park in Santa Monica, California, with a view of the iconic Ferris wheel and pier, all reflected in the seawater below
A night view of the neon-lit fun park in Santa Monica, California, with a view of the iconic Ferris wheel and pier, all reflected in the seawater below
The first month of the autumn, September, is also an agreeable month in Santa Monica, California, with average temperature ranging between min 63°F (17.2°C) and max 71.1°F (21.7°C).

Temperature

The warmest months are August and September, with an average high-temperature of 71.1°F (21.7°C).

Rainfall

In Santa Monica, during September, the rain falls for 1 days and regularly aggregates up to 0.1" (3.3mm) of precipitation. In Santa Monica, during the entire year, the rain falls for 32.7 days and collects up to 12.8" (324.9mm) of precipitation.

Ocean temperature

August through October, with an average ocean temperature of 66.2°F (19°C), are months with the warmest seawater in Santa Monica.
Note: Swimming in 66.2°F (19°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

Daylight

In September, the average length of the day in Santa Monica is 12.4h.

Sunshine

The average sunshine in September is 9h.

UV index

In September, the average daily maximum UV index is 8. A UV Index reading of 8 to 10 represents a very high threat to health from the exposure to the Sun's UV radiation for the average person.
Note: In September, the average maximum UV index of 8 translate into the following recommendations:
Take extra precautions. Fair-skinned individuals may get burned in less than 10 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What are the warmest months in Santa Monica?

Warmest months in Santa Monica, California, are August and September, with an average high-temperature of 71.1°F (21.7°C).

What is the temperature in September in Santa Monica?

In Santa Monica, California, in September, the average high-temperature is 71.1°F (21.7°C), and the average low-temperature is 63°F (17.2°C).

How many days does it rain in September in Santa Monica?

In Santa Monica, California, during September, the rain falls for 1 days and regularly aggregates up to 0.1" (3.3mm) of precipitation.

What are the months with the warmest ocean in Santa Monica?

August through October, with an average ocean temperature of 66.2°F (19°C), are months with the warmest seawater.

What is the ocean temperature in September in Santa Monica?

In September, the average ocean temperature is 66.2°F (19°C). For swimming, a surface water temperature of 66.2°F (19°C) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 69.8°F (21°C).

What is the average length of the day in September in Santa Monica?

In September, the average length of the day in Santa Monica, California, is 12.4h.

How many hours of sunshine does Santa Monica have in September?

In Santa Monica, California, the average sunshine in September is 9h.

What is the UV index intensity in September in Santa Monica?

The average daily maximum UV index in September in Santa Monica is 8. A UV Index reading of 8 to 10 represents a very high health threat from the exposure to the Sun's UV radiation.
Average temperature in September - Santa Monica, CA
  • Average high temperature in September: 71°F

Warmest months (with the highest average high temperature) are August and September (71°F).
Months with the lowest average high temperature are February and March (63°F).

  • Average low temperature in September: 63°F

Months with the highest average low temperature are July, August and September (63°F).
Coldest months (with the lowest average low temperature) are January and December (51°F).

Average rainfall in September - Santa Monica, CA
  • Average rainfall in September: 0.1"

The wettest month (with the highest rainfall) is February (3.4").
Driest months (with the lowest rainfall) are June, July and August (0").

Average rainfall days in September - Santa Monica, CA
  • Average rainfall days in September: 1 days

The month with the highest number of rainy days is February (7.9 days).
The month with the lowest number of rainy days is July (0.1 days).

Average sea temperature in September - Santa Monica, CA
  • Average sea temperature in September: 66°F

Best months for swimming (with the highest average sea temperature) are August, September and October (66°F).
Coldest months (with the lowest average sea temperature) are January, February, March, April, May and December (59°F).

Average daylight in September / Average sunshine in September - Santa Monica, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.4h).
The month with shortest days is December (Average daylight: 9.9h).

  • Average sunshine in September: 9h

The month with most sunshine is July (Average sunshine: 12h).
Months with least sunshine are January, November and December (Average sunshine: 7).

Average UV index in September - Santa Monica, CA
  • Average UV index in September: 8

The month with the highest UV index is July (UV index 11).
Months with the lowest UV index are January and December (UV index 3).