Weathermondo.com
United StatesThe weather in September in San Diego
It's warm in September in San Diego with an average temperature of 26°C. Temperatures this month range from a low of 25°C to a high of 28°C. At night, you can expect temperatures between 19°C and 22°C.
Looking for great weather? September is a good time to be in San Diego. The temperatures are nice, and there’s not too much rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for San Diego, California. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 38°C in 2016, San Diego reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 20°C in 2023. The extreme nighttime temperatures ranged from a lowest recorded value of 13°C to a highest value of 27°C.
Water temperature
The water temperature at San Diego is 21°C this month. Pleasant for a swim.
Rainfall amount
According to weather history, there is only 6,7 mm of precipitation in September. The wind speed is around 4 Bft, mostly coming from the West.
Daily weather in September for San Diego
Click on any day in September to get detailed info about the usual weather on that day in San Diego. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| San Diego | New York | |
|---|---|---|
| Average temperature | 26°C | 27°C |
| Max. temperature | 28°C | 31°C |
| Min. temperature | 19°C | -5°C |
| Total precipitation | 6,7 mm | 57 mm |
| Rainy days | 2 days | 9 days |
Start of September
The month of September starts in San Diego with hot temps, averaging around 28°C during the day and nights around 22°C.
Mid September
By mid-September, daytime temps drop to around 26°C, with nights around 21°C. Not much precipitation expected during this period. It’s mostly dry and sunny.
End of September
By the end of September, the average daytime temperature in San Diego is around 26°C, while nighttime temps are about 20°C. There’s hardly any chance of precipitation. The weather will be mostly dry with plenty of sun.
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UV index
The UV index is a maximum of 8 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
Check out the climate of San Diego for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in September in San Diego, California. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in San Diego
Temperature in September in San Diego over the years
Precipitation charts
These charts show the average amount of precipitation in September in San Diego, California. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in San Diego
Total precipitation in September in San Diego over the years
Daily UV index in September in San Diego
This chart shows the average daily UV index in September in San Diego, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in San Diego
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Average weather in San Diego by month
Click on a month below to see detailed weather info for San Diego. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.