Sasha,
I was out hiking a ridge in the Santa Monica mountains this afternoon and we experienced a thunderstorm. I agree that's very unusual for LA in late May.
If you have a few bucks to spare, check out some of the ultralight backpacking websites and see if you can decrease your load. Makes backpacking a lot more pleasant. When you are older (and if you get heavier like me), it will really pay off.
They just had a free ultralight backpacking seminar at A16 near Pico & Sepulveda on 5/19. Some of the other stores may have one scheduled over the next couple weeks. It is put on by a respected manufacturer of UL gear and might be pretty useful.
Have fun!
DancesWithKnives