weather in california in september

Where in California? It's a big place.

Size wise it would be as if you took England and Scotland and doubled it in size.

The distance from top to bottom of the state is similar to the distance between London and Nice or Rome and Cologne. (approx. 1000 km)

That said it will be cooler in the north (but not cold), warmer in the south, still hot in the desert, and you might need a jacket if up in the mountains. If, like most people, you'll be staying near the coast, the weather can range from hot to cool (especially at night). Pack a sweater or light jacket. And shorts for the south or desert.

In most of California it is still summer early in September. Mostly it is a good month to be here, even in the mountains. In the San Francisco Bay Area, the summer fog usually disappears in September. Crowds are smaller, so Sept. can be an ideal month in California.

Hi Marilyn, we here in California, have "micro-climates". It can be 20 degrees F warmer in a city one hour drive away. September is still summer and can be very hot. The good news is that, it usually cools down quite a bit at night so sleeping is comfortable. It is also very dry (so much so that we have "fire seasons") so humidity isn't usually an issue.

September is somewhat warm (you can wear shorts still, but it's not generally unbearable) in S. Cal, and it's one of the smoggiest months in the LA area.

It depends on where you are going. The coast is generally cooler than inland. Northern CA can be cooler than Southern CA, unless you are in the central valley, then all bets are off. The mountains can be warm during the day, but freezing at night. You should check specifically for where you plan to go.