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
San Diego experiences an average high-temperature of a still moderately hot 76.6°F (24.8°C) in September, marking an insignificant shift from 77.4°F (25.2°C) in August. In September, San Diego's temperature tends to fall to an average low of 65.1°F (18.4°C) during the night.Humidity
In San Diego, California, the average relative humidity in September is 68%.Rainfall
In September, the rain falls for 4.5 days. Throughout September, 0.39" (10mm) of precipitation is accumulated. Throughout the year, in San Diego, there are 61.8 rainfall days, and 8.7" (221mm) of precipitation is accumulated.Ocean temperature
In September, the average ocean temperature is 66.7°F (19.3°C).Note: Swimming is not a pleasurable activity for the majority in water at 66.7°F (19.3°C). Breathing control gets harder as the water temperature dips from 69.8°F (21°C) to 59°F (15°C).
Daylight
In September, the average length of the day in San Diego is 12h and 22min.On the first day of September in San Diego, sunrise is at 6:23 am and sunset at 7:12 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:34 pm PDT.
Sunshine
In San Diego, the average sunshine in September is 10.3h.UV index
July 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 risk from exposure to the Sun's UV radiation for ordinary individuals.Note: A typical high UV index of 6 in September suggests the following recommendations:
Inhibit overexposure. Warding off sun damage is of utmost importance. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in San Diego?
What is the average humidity in September in San Diego?
How much does it rain in San Diego in September?
How cold is the water in September in San Diego?
What is the average length of the day in September in San Diego?
When is the sunrise / sunset in September in San Diego?
How many hours of sunshine does San Diego have in September?
What is the month with the highest UV index in San Diego?
How high is the UV index in September in San Diego?
Average temperature in September
San Diego, CA
- Average high temperature in September: 76.6°F
The warmest month (with the highest average high temperature) is August (77.4°F).
The month with the lowest average high temperature is February (63.1°F).
- Average low temperature in September: 65.1°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (51.8°F).
Average pressure in September
San Diego, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are June and September (29.88"Hg).
Average wind speed in September
San Diego, CA
- Average wind speed in September: 5.4mph
The windiest months (with the highest average wind speed) are April and May (6.3mph).
The calmest month (with the lowest average wind speed) is October (5.2mph).
Average humidity in September
San Diego, CA
- Average humidity in September: 68%
The month with the highest relative humidity is June (73%).
The month with the lowest relative humidity is November (59%).
Average rainfall in September
San Diego, CA
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is June (0.12").
Average rainfall days in September
San Diego, CA
- Average rainfall days in September: 4.5 days
The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (2.7 days).
Average sea temperature in September
San Diego, CA
- Average sea temperature in September: 66.7°F
The best month for swimming (with the highest average sea temperature) is August (67.9°F).
The coldest month (with the lowest average sea temperature) is February (58.7°F).
Average daylight in September /
Average sunshine in September
San Diego, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 2min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
San Diego, CA
- Average sunshine days in September: 21.8 days
The month with the most sunshine days is January (24.3 days).
The month with the least sunshine days is July (20.3 days).
Average UV index in September
San Diego, 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
San Diego, CA
- Average cloud cover in September: 12
The month with the most cloud cover is December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 9).
Average visibility in September
San Diego, 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).
San Diego, California, USA
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