CO Rick gave you some good advice. It can be in the 80's one day and snowing the next............or both of those in the same day!!!!!!!!!!!!!
One thing he said you really want to pay attention to is.........when the sun goes down it gets COLD! Which brings up sleeping bags. I personally would bring a bag that is a little heavier than you would think you would need. Theres nothing worse than shivering in a light bag all night long.
Good luck on your hunt