Looks like you are planning E to W. IMO the trick is to not be caught by unexpected weather. The eastern half of the ride should be pretty stable weather that time of year. Fairly simple to look at a weather app to see what you are dealing with. The desert portion from mid-TX to the imperial valley in CA can get colder or hotter that time of year with the added possible issue of winds. The last 90-ish miles in to San Diego is mountains. You could be in 80f weather in the Imperial valley and 50f and strong winds 20 miles later followed by fog 40 miles further along.
I would make the effort to look ahead at weather conditions so I can plan gear changes. If you read reports of this ride you will notice the CA mountain section gets mentioned alot for it's weather. Weather Underground, for one web source, lets you look at historic weather conditions. The ride seems very doable that time of year. Good Luck!