September weather forecastLa Jolla, CA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in La Jolla, California, with an average temperature varying between 64.4°F (18°C) and 78.6°F (25.9°C).Temperature
August's transformation into September witnesses an average high-temperature of a still moderately hot 78.6°F (25.9°C), noting a minor change from the preceding month. La Jolla witnesses an average low-temperature of 64.4°F (18°C) throughout the month of September.Humidity
In La Jolla, the average relative humidity in September is 65%.Rainfall
In La Jolla, during September, the rain falls for 4.2 days and regularly aggregates up to 0.31" (8mm) of precipitation. Throughout the year, there are 57.9 rainfall days, and 7.48" (190mm) of precipitation is accumulated.Ocean temperature
In La Jolla, in September, the average water temperature is 66.7°F (19.3°C).Note: The majority of individuals find it unpleasurable to swim in 66.7°F (19.3°C). It becomes progressively harder to manage one's breathing as the water temperature falls below 69.8°F (21°C).
Daylight
In September, the average length of the day is 12h and 22min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:13 pm. On the last day of September, sunrise is at 6:43 am and sunset at 6:34 pm PDT.
Sunshine
In September, the average sunshine 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 of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for the ordinary person.Note: The average daily UV index of 6 in September transforms into the following instructions:
Guard oneself from overexposure. Defence against sun injury is vital. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. 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
La Jolla, CA
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is August (79.3°F).
The month with the lowest average high temperature is December (63.5°F).
- Average low temperature in September: 64.4°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (50.2°F).
Average pressure in September
La Jolla, 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
La Jolla, CA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is April (6mph).
The calmest month (with the lowest average wind speed) is October (4.8mph).
Average humidity in September
La Jolla, CA
- Average humidity in September: 65%
The months with the highest relative humidity are May and June (71%).
The month with the lowest relative humidity is November (57%).
Average rainfall in September
La Jolla, CA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is February (1.46").
The driest month (with the least rainfall) is June (0.12").
Average rainfall days in September
La Jolla, CA
- Average rainfall days in September: 4.2 days
The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (2.2 days).
Average sea temperature in September
La Jolla, 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
La Jolla, CA
- Average daylight in September: 12h and 24min
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 18min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).
Average sunshine days in September
La Jolla, CA
- Average sunshine days in September: 22.4 days
The month with the most sunshine days is January (24.8 days).
The month with the least sunshine days is February (20.2 days).
Average UV index in September
La Jolla, 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
La Jolla, CA
- Average cloud cover in September: 11
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 8).
Average visibility in September
La Jolla, 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).
