Best Bag temp rating for Summer time

[5th]

I used a 45deg down bag for summer and a 30deg down bag for winter for hiking in the Three Sisters area for over a decade. Now I use 30 deg quilt, but that's because I haven't bought a lighter one yet. If I'm cold I add clothing, but that rarely happens. If you are going anytime mid-July through mid-October, any light bag should do, IMO.

[AAdamsPDX]

... Now I use 30 deg quilt, but that's because I haven't bought a lighter one yet.

Extra upvote for the quilt! Really light compared to a sleeping bag. My 20 degree quilt (a "short" size) is just 17 ounces. Because it's a quilt and not a bag, I stay comfortable in just about any temperature down to below 30. For warmer temps, just cover up a little. For colder, wrap up well and/or add a hooded down jacket.

My husband has a 30 degree quilt and was sometimes cold at higher elevations last summer: though we were at 10,000 feet, not the 5,000 you'd hit in the Sisters!

http://www.enlightenedequipment.com/