September weather forecast and climate
Long Beach, CA

A colorful sunset sky over the Pacific Ocean in Long Beach, California
A colorful sunset sky over the Pacific Ocean in Long Beach, California

Weather in September

The first month of the autumn, September, is also a moderately hot month in Long Beach, California, with average temperature fluctuating between 64.8°F (18.2°C) and 78.8°F (26°C).

Temperature

In September, the average high-temperature is essentially the same as in August - a still warm 78.8°F (26°C). The average low-temperature, is 64.8°F (18.2°C).

Humidity

In Long Beach, California, the average relative humidity in September is 63%.

Rainfall

In Long Beach, California, during 3.3 rainfall days, 0.24" (6mm) of precipitation is typically accumulated. Throughout the year, there are 47.2 rainfall days, and 5.59" (142mm) of precipitation is accumulated.

Ocean temperature

In September, the average ocean temperature in Long Beach is 66.7°F (19.3°C).
Note: For most, swimming in 66.7°F (19.3°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

Daylight

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

Sunshine

In Long Beach, California, the average sunshine in September is 10.6h.

UV index

June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health vulnerability from the exposure to the Sun's UV radiation for ordinary individuals.
Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the temperature in September in Long Beach?

The average high-temperature, in September, in Long Beach, California, is 78.8°F (26°C), while the average low-temperature is 64.8°F (18.2°C).

What is the average humidity in September in Long Beach?

In September, the average relative humidity is 63%.

How many days does it rain in September in Long Beach?

In September, in Long Beach, California, the rain falls for 3.3 days. Throughout September, 0.24" (6mm) of precipitation is accumulated.

What is the ocean temperature in September in Long Beach?

In Long Beach, California, the average seawater temperature in September is 66.7°F (19.3°C). For swimming, a surface water temperature of 66.7°F (19.3°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 Long Beach?

The average length of the day in September is 12.4h.

How many hours of sunshine does Long Beach have in September?

In September, the average sunshine in Long Beach is 10.6h.

When is the highest UV index in Long Beach?

Months with the highest UV index in Long Beach are June through September, with an average maximum UV index of 6.

How high is the UV index in September in Long Beach?

In Long Beach, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health threat from the exposure to the Sun's UV rays.

Average temperature in September
Long Beach, CA

Average temperature in September - Long Beach, CA
  • Average high temperature in September: 78.8°F

The warmest month (with the highest average high temperature) is August (79.5°F).
The month with the lowest average high temperature is December (63.5°F).

  • Average low temperature in September: 64.8°F

The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (52°F).

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Average pressure in September
Long Beach, CA

Average pressure in September - Long Beach, CA
  • Average pressure in September: 29.89"

The month with the highest atmospheric pressure is January (30.1").
Months with the lowest atmospheric pressure are June and September (29.89").

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Average wind speed in September
Long Beach, CA

Average wind speed in September - Long Beach, CA
  • Average wind speed in September: 5mph

The windiest month (with the highest average wind speed) is April (6.5mph).
The calmest months (with the lowest average wind speed) are September and October (5mph).

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Average humidity in September
Long Beach, CA

Average humidity in September - Long Beach, CA
  • Average humidity in September: 63%

The month with the highest relative humidity is June (71%).
The month with the lowest relative humidity is November (55%).

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Average rainfall in September
Long Beach, CA

Average rainfall in September - Long Beach, CA
  • Average rainfall in September: 0.24"

The wettest month (with the highest rainfall) is December (1.14").
The driest month (with the least rainfall) is June (0.08").

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Average rainfall days in September
Long Beach, CA

Average rainfall days in September - Long Beach, CA
  • Average rainfall days in September: 3.3 days

The month with the highest number of rainy days is March (6 days).
The month with the least rainy days is June (1.8 days).

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Average sea temperature in September
Long Beach, CA

Average sea temperature in September - Long Beach, CA
  • Average sea temperature in September: 66.7°F

The best months for swimming (with the highest average sea temperature) are July and August (67.9°F).
The coldest month (with the lowest average sea temperature) is January (58.3°F).

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Average daylight in September /
Average sunshine in September
Long Beach, CA

Average daylight in September / Average sunshine in September - Long Beach, CA
  • Average daylight in September: 12.4h

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

  • Average sunshine in September: 10.6h

Months with the most sunshine are July and August (Average sunshine: 12h).
Months with the least sunshine are January, February and December (Average sunshine: 6.8).

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Average sunshine days in September
Long Beach, CA

Average sunshine days in September - Long Beach, CA
  • Average sunshine days in September: 22.7 days

The month with the most sunshine days is January (25.7 days).
The month with the least sunshine days is June (20.8 days).

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Average UV index in September
Long Beach, CA

Average UV index in September - Long Beach, CA
  • Average UV index in September: 6

Months with the highest UV index are June, July, August and September (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 4).

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Average cloud cover in September
Long Beach, CA

Average cloud cover in September - Long Beach, CA
  • Average cloud cover in September: 9

Months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 7).

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Average visibility in September
Long Beach, CA

Average visibility in September - Long Beach, CA
  • Average visibility in September: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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