When to plant onion sets in Calif. in the fall

Question

I live in North Los Angeles, not near the ocean.

Answer 1

Look for short-day growing varieties, they need 10 to 12 hours of sunlight and will do well in Southern CA.
An onion's variety requirements determine the time to plant but you can plant most varieties between September and March.
Short-day varieties are planted November through January and you can expect a harvest in late spring to early summer.

https://www.gardeningknowhow.com/edible/vegetables/onion/find-how-to-grow-onions-in-your-garden.htm