Hey all,

Whats the consensus on the proper rating for a sleeping bag to be used in Yosemite, Yellow Stone, Mammoth, JMT late spring through mid-fall?

I don't want to get a bag that is too hot or too cold. I like to be warm when i sleep, but I guess i can always layer up in extreme cases. It's easier to unzip the bag than carry extra clothes if it's not properly rated IMHO.

So - 15*, 20*, 30*...?

Edited by Yazon on 07/11/2011 14:55:03 MDT.

15 degrees. 20 degrees with a hooded down jacket should get you down to 15 degrees.

I wear a 30 degree bag and carry a bivy and a full suite of down clothing for sunrise photography. Basically, +5 for bivy, +5 for hooded down jacket, +5 for down pants/socks.

I operate around Yosemite to Sequoia from late spring to early autumn. I use a 32 degree F rated down bag. But you will see a lot of variation due to elevation. There are low elevation places in Yosemite that wouldn't get below 50 F now, and there are high elevation places in Sequoia that still have five feet of snow over the frozen trail.

If you don't know what you need, then you ought to get something that is about 10 degrees F _better_ than what you think you need, just as a safety factor.

I've never thought of Yellowstone Park as West Coast.

--B.G.--

Yea, not sure why i've put Yellowstone, was thinking about another place when i wrote it. My bad...

I was there in mid-June, and lots of the normal places in the park had snow cover. The last of the ice was melting in Yellowstone Lake. I believe the coldest that I felt there was 29 F on some mornings before dawn.

But, it is starting to warm up there now, so the grizzly bears are coming out to romp around (judging by the human fatality due to mauling last week).

--B.G.--

I figured Yellowstone was a mistake... Yosemite will be the coldest you've listed:
http://www.nps.gov/yose/planyourvisit/climate.htm

Note the higher elevations in fall is when you'll be sleeping down to 15 degrees (subtract 10 degrees from average lows, and subtract 20 degrees for higher elevation), as I assume you won't be sleeping on snow at high elevations in spring. You can get by with a 30 degree bag (+down jacket) if you don't hit the higher elevations much, and/or skip trips when the lows approach records.

Looking at the numbers it seems that 20-30* bag should be sufficient for most of what i plan on doing.

Since i will be sleeping in a tent most of the time - it should make it even more comfortable. I will be taking hammock when the temperatures in the upper range and few extra degrees are not as critical.