A couple questions about the Southern California Section of the trail:
Slick B
Depends on the weather and the elevation. Though chances are April will be sunny, in some years there can be a late winter storms as late as May (though the chances are less the latter in the year it is) which dump snow on the higher elevations and drop temperatures everywhere.
Even if there is no storm, temperatures can drop below freezing in the desert at night since there is no moisture to hold the heat. There are several mountain ranges in SoCal that you will have to travel over which will take you over 8000ft in elevation where the temperature will be even colder. I wouldn’t try to use a sleeping bag rated higher then 30F and some people go for an even warmer bag.
There is a lot of stakeable ground, but sometimes you will be in sandy conditions. Uusually a large rock over your stake is adequate unless the wind is blowing good. Most people don’t bother with snow/sand stakes, but carrying a couple might not be a bad idea; especially since you can use one as your cathole shovel.
Miner
I think Miner’s post is accurate. In two different years ('97 & '05) I experienced freezing temps occasionally in the desert at night, and very cold temps. near San Jacinto (in the teens). At least its a low humidity cold, which isn’t as ‘biting’ as an East Coast cold at the same temp.
As for stakeable ground - i would say virtually all of the terrain is stakeable.
Happy Trails!
freebird