Temperatures in September
It's hot in September in California with an average temperature of 33°C. Temperatures this month range from a low of 29°C to a high of 38°C. At night, you can expect temperatures between 15°C and 20°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for California in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in California with hot temperatures, averaging around 37°C during the day and nights close to 20°C. You won’t see any precipitation in the first days of the month, it’s all sunny skies.
Mid-September
By mid-September, the average daytime temperature drops to around 33°C, with nights close to 18°C. No precipitation expected during this period, so you can enjoy plenty of sunshine.
Temperatures vary between day and night, so it’s smart to wear layers.
End of September
By the end of September, the average daytime temperature in California will be around 32°C, with nights close to 17°C. No precipitation expected, with plenty of sunshine on the horizon.
As it gets cooler in the evening, it’s best to wear layers.
Discover cheap holidays to California 
Precipitation in September
According to weather history, there is only 1 mm of precipitation in September. The wind speed is around 3 Bft, mostly coming from the West.
The average chance of precipitation is only 1% in September.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for California. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
California in September |
UK | ||
|---|---|---|---|
 Average Temperature |
33°C | 20°C | |
 High Temp |
38°C | 22°C | |
| Low Temp |
29°C | 17°C | |
 Total Precipitation |
1 mm | 44 mm | |
| Rainy Days |
0 days | 8 days | |
August
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.
Is September a good time to visit California?
September is a fantastic month to be in California for sunny weather. You’ll get high temperatures and little chance of rain this month.
Temperature records for California in September
With 46°C, California hit the highest temperature in the last 10 years in September 2022. The lowest daytime temperature in this month was 21°C in 2017. The extreme night temperatures ranged from a low of 9°C to a high of 28°C.
Check out the climate of California for all months and discover the best travel time
The climate of California is based on weather data from . Other spots, like New York City, Miami or Los Angeles, might have different weather. You can check out all destinations in California for a full picture of the climate.
Plan your next holiday
Don’t miss the best holiday deals for California and see what our partners have for you.
Daily Temperature in September in California
This chart shows the average daily temperatures, both day and night, for each day in September in California, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in California
The chart below shows the average daily precipitation in September for California, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect it to stay dry all month in California.
Daily UV Index in September in California
This chart shows the average daily UV index in September in California, 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.
Temperature in September in California Over the Years
This chart shows the average temperature in September in California, measured in degrees Celsius, over the past years.
Total Precipitation in September in California Over the Years
This chart shows the average precipitation in September in California, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for California
Click on a specific day in September for detailed info on the typical weather on that day in California. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in California
Have you been to California in September?
Share your weather experience in September in California.
Average Weather in California by Month
Click on a month below to see detailed weather info for California. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of California for all months at once
