sleeping bag for summer on JMT

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grugs
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sleeping bag for summer on JMT

Post by grugs »

I am planning to take a 40 degree bag for an early august trip on the JMT. What are your thoughts on carrying the light bag and wearing my insulation layer to sleep, which I have to carry anyway, to boost the warmth of the bag. Trying to avoid buying a new bag and at the same time, lighten the load. I am carrying a tent instead of tarp to increase warmth. Do you think this will be warm enough?
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oldranger
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Re: sleeping bag for summer on JMT

Post by oldranger »

Grugs

I doubt you will be happy with a 40 degree bag. I use 20 degree bag and beginning the last week of august bring an extra pair of light long underwear to double up if it gets cold. But I sleep cold. Temps in the low 20s can happen anytime though not often in August. I couldn't recommend a bag designed for temps over 30 to anyone and think for summer a 20 degree bag is best for elevations around 10,000ft +/-. Carrying sufficient extra clothes to make a 40 degree bag work will increase the volume and weight of your load considerably more than a high quality bag with a suitable temperature range. That being said if you can handle the increased load (and already have the needed layers) easier than the cost of a new bag then do what you have to do. However the cost of a high quality bag amortize over its life expectancy if taken care of is not likely to be as expensive as it might seem when slapping down your hard earned cash. Markskor, who is seldom wrong about things backpacking, has a saying that goes something like this, "Buy the best and you won't be sorry!"
I still have a functional North Face bag I bought in 1969 that is still functional with plenty of loft that is semi retired because new fabrics and even higher quality down enabled me to find a bag that is as warm but weighs half as much.

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The Other Tom
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Re: sleeping bag for summer on JMT

Post by The Other Tom »

I agree with Mike. I use a 20 degree bag and "extra clothes" to stay warm. I've seen it as low as 22 in August.
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hikerduane
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Re: sleeping bag for summer on JMT

Post by hikerduane »

You are taking a chance, if you were only going for a night, I would say go for it. I know some folks about three years ago, who were snowed on in early August and then it got down into the low 20's. Then there was the issue of hiking thru the snow, over a pass that day. I use a 35 degree down bag for my summer Sierra trips and wish I had a 30 degree bag. I hope your insulating clothes at least include a coat, gloves, watch cap. I hate sleeping in too many clothes.
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markskor
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Re: sleeping bag for summer on JMT

Post by markskor »

Grugs,
If doing the Muir, an epic trip, nothing will spoil your journey faster than not being able to get a good night's sleep. Echo all above responses, a good down bag, rated to at least 25º is mandatory ... 20º even better.
There will be times when all you will want to do is crash, get warm, and recover - been there.
Skimping now...well, you will invariably regret it later, hopefully not at 12,000 feet, in the rain, when there is nothing else you can do but shiver. Being warm and dry always solves a multitude of Sierra sins.

As Mike alluded to, my backpacking mantra:

Buy the best gear;
(You will always regret settling for anything less.)
Take what pleases you -
Hike safe -
Eat well.
It weighs what it weighs -
Nobody is asking you to carry it.
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maverick
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Re: sleeping bag for summer on JMT

Post by maverick »

20 for me also is the magic number, and well worth the investment, especially when it
comes to a sleeping bag.
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ever need from spring to early fall in the Sierra.
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LMBSGV
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Re: sleeping bag for summer on JMT

Post by LMBSGV »

Another vote for 20 degrees or lower. I don't know what the exact temperatures were, but I've had water bottles freeze inside the tent in August. If finances are a consideration, you might try the REI Outlet online. When the down bag I used for 20+ years finally died, I found a great replacement there - lightweight, rated 15 degrees, and at quite a low price.
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paul
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Re: sleeping bag for summer on JMT

Post by paul »

grugs wrote: I am carrying a tent instead of tarp to increase warmth.
Weight-wise, you are better off with a warmer bag rather than a tent. Cost-wise, taking what you already have is obviously cheaper.
You can bet on seeing temperatures in the low 30's, and you are likely to see some in the 20's. If you have used your combination of bag, clothing, pad (important factor there) and tent in those temps then go for it. If not, test it out in those temps before you go, and do it on a night when you are really tired and haven't eaten well and with some of your clothing a little bit damp.
I use a 30 degree bag for Sierra summer trips, and that works well for me if using a tent or bivy sack. If I were tarping it with no bivy, I'd want a 20 degree bag.
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vandman
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Re: sleeping bag for summer on JMT

Post by vandman »

A 20 degree bag is perfect. My last 2 trips were in August, and on both trips it got down to 20 degrees a few times. One thing you don't want to skimp on is a good bag, you have to get a good night's sleep.
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Carne_DelMuerto
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Re: sleeping bag for summer on JMT

Post by Carne_DelMuerto »

Add another vote for a 20 degree bag. I've never had an issue in the Sierra with mine. Steep and Cheap has had quite a few sleeping bags cycling through lately, although most have been 0 or 30 degree bags. There was one 20 degree bag from Mountainsmith...I don't know much about that brand, but I did buy one for my wife for car camping. Out of the box it looked like a good quality bag. You've got some time to sniff out a deal.
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