Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September's onset records a minor alteration in the average high-temperature to a still moderately hot 77°F (25°C) from August's 77.4°F (25.2°C). During September, Seal Beach records a consistent average nighttime temperature of 64.6°F (18.1°C).Humidity
In September, the average relative humidity is 67%.Rainfall
In Seal Beach, in September, during 3 rainfall days, 0.2" (5mm) of precipitation is typically accumulated. In Seal Beach, during the entire year, the rain falls for 57.8 days and collects up to 8.82" (224mm) of precipitation.Ocean temperature
In Seal Beach, the average seawater temperature in September is 66.7°F (19.3°C).Note: The majority of individuals find swimming in 66.7°F (19.3°C) to be unenjoyable. The difficulty in controlling breathing rises as the temperature decreases from 69.8°F (21°C) to 59°F (15°C).
Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:37 pm PDT.
Sunshine
In September, the average sunshine in Seal Beach is 10.6h.UV index
July through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the average person.Note: The maximum UV index, 6 during September, leads to the following recommendations:
Guard against overexposure. Protection from sun-induced harm is essential. Seek shade and limit direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Keep in mind that shade structures like parasols or canopies do not offer complete sun protection. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September in Seal Beach?
How many days does it rain in September?
How cold is the water in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the month with the highest UV index?
How high is the UV index in September?
Average temperature in September
Seal Beach, CA
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is August (77.4°F).
The month with the lowest average high temperature is December (62.8°F).
- Average low temperature in September: 64.6°F
The month with the highest average low temperature is August (65.3°F).
The coldest month (with the lowest average low temperature) is February (52.7°F).
Average pressure in September
Seal Beach, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.89"Hg).
Average wind speed in September
Seal Beach, CA
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is April (6.7mph).
The calmest months (with the lowest average wind speed) are August, September and October (5.3mph).
Average humidity in September
Seal Beach, CA
- Average humidity in September: 67%
The month with the highest relative humidity is June (73%).
The month with the lowest relative humidity is November (57%).
Average rainfall in September
Seal Beach, CA
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is December (1.77").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Seal Beach, CA
- Average rainfall days in September: 3 days
The month with the highest number of rainy days is March (8.1 days).
The months with the least rainy days are June and August (2.3 days).
Average sea temperature in September
Seal 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).
Average daylight in September /
Average sunshine in September
Seal Beach, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 4min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Seal Beach, CA
- Average sunshine days in September: 25.5 days
The month with the most sunshine days is August (26.3 days).
The month with the least sunshine days is February (19.3 days).
Average UV index in September
Seal Beach, CA
- Average UV index in September: 6
The months with the highest UV index are July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).
Average cloud cover in September
Seal Beach, CA
- Average cloud cover in September: 10
The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 7).
Average visibility in September
Seal Beach, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Seal Beach, California, USA
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