It's set to rain for 5 days straight in LA and most trails are closed for 48 hours after the latest rainfall (due to the loose and often sandy nature of our trails they are very sensitive to erosion) so you might not get the warm weather you are looking for - the average high temp for the past 3 weeks has been ~50-60F.
But if you want to do something real special, I'd recommend Catalina:
https://www.bikeovernights.org/post/...atalina-island