September weather forecastOpal Cliffs, CA
September
Weather in September
September, the first month of the autumn in Opal Cliffs, is also an agreeable month, with an average temperature fluctuating between 73°F (22.8°C) and 55.2°F (12.9°C).Temperature
The peak of Opal Cliffs's temperatures is noted during August and September, averaging a high-temperature of 73°F (22.8°C).Humidity
The average relative humidity in September in Opal Cliffs is 70%.Rainfall
In Opal Cliffs, in September, it is raining for 2.7 days, with typically 0.12" (3mm) of accumulated precipitation. Throughout the year, there are 77.9 rainfall days, and 14.45" (367mm) of precipitation is accumulated.Ocean temperature
The months with the warmest seawater are August and September, with an average ocean temperature of 58.1°F (14.5°C).Note: If planning to swim in 58.1°F (14.5°C) under 50°F (10°C), wear a protective suit. Neglecting this advice might cause immediate cold shock and troubled breathing. A splash around 55.4°F (13°C) is not much warmer.
Daylight
In September, the average length of the day is 12h and 24min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:35 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:52 pm PDT.
Sunshine
In Opal Cliffs, California, the average sunshine in September is 10.9h.UV index
June through September, with an average maximum UV index of 5, are months with the highest UV index. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the average person.Note: The average daily UV index of 5 in September transforms into the following instructions:
Ensure safety - Sun damage prevention is strongly urged. To protect against the Sun's most potent rays, avoid direct exposure around midday. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Opal Cliffs, CA
- Average high temperature in September: 73°F
The warmest months (with the highest average high temperature) are August and September (73°F).
The month with the lowest average high temperature is December (57.2°F).
- Average low temperature in September: 55.2°F
The month with the highest average low temperature is September (55.2°F).
The coldest month (with the lowest average low temperature) is February (45.5°F).
Average pressure in September
Opal Cliffs, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in September
Opal Cliffs, CA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is April (7.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in September
Opal Cliffs, CA
- Average humidity in September: 70%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Opal Cliffs, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is December (2.8").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Opal Cliffs, CA
- Average rainfall days in September: 2.7 days
The month with the highest number of rainy days is March (13.4 days).
The month with the least rainy days is August (1.2 days).
Average sea temperature in September
Opal Cliffs, CA
- Average sea temperature in September: 58.1°F
The best months for swimming (with the highest average sea temperature) are August and September (58.1°F).
The coldest month (with the lowest average sea temperature) is April (53.8°F).
Average daylight in September /
Average sunshine in September
Opal Cliffs, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 10h and 54min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Opal Cliffs, CA
- Average sunshine days in September: 26.3 days
The month with the most sunshine days is August (27.8 days).
The month with the least sunshine days is March (16.4 days).
Average UV index in September
Opal Cliffs, CA
- Average UV index in September: 5
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February and November (UV index 3).
Average cloud cover in September
Opal Cliffs, CA
- Average cloud cover in September: 15
The month with the most cloud cover is March (Cloud cover 38).
The months with the least cloud cover are July and September (Cloud cover 15).
Average visibility in September
Opal Cliffs, 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).
