How many F degrees of warmth can a silk sleeping liner and a LW down puffy add?

Franco, you can get a 0C bag (32F) down to -7C (19F), right?

BUT
I need to get down to -15C (5F) and I can only purchase a man sleeping bag, due to my height.

So, following your parameters, I would need to buy a -8C (17F), but, since I'm a woman, I would need to take off 11F more from that, getting a 6F bag and that's bulky!

I wouldn't be too worried; really I doubt you'd need anything more than a 20F bag until you reach Argentina, and even then that may be plenty depending on season. Yes, that includes the Andes, assuming you aren't planning on climbing 6000m peaks.

Edit: to be slightly less off-topic; in which areas are you expecting to see 5F? At some point, renting (a bag or a room) may be the better option.

I know it's frustrating, but this isn't really a question of math. As others have said, only your own experience can tell you whether something will work. You can't just start adding and subtracting other's experiences.

I don't like spending any more than I have to, and I absolutely hate buying something only to find it doesn't work for what I bought it for. Unfortunately, that's a reality of buying gear. (Unless you don't mind being a thorn in REI's side)

This is not true. I had friends going to many parts of Bolivia and encountering 5F at night. In Patagonia there were -25C and up to -30C.
And they did not have heating systems anywhere inside.

I've gone back and forth on this a few times. I've tried several systems ranging from a very warm bag and minimal clothing to very warm clothing and virtually no bag. In the end, adding weight to the bag insulation is almost always a lighter option than bringing extra clothing or bringing something like a liner. I would suggest that you bring whatever clothing insulation you're likely to need to sit/rest comfortably in the evening and morning and no more. Put the rest of your weight into bag insulation. A versatile way to do this is to use a quilt rather than a bag. You can get a warmer quilt and vent it when it's too warm.

I read through this blog the other day and had an "aha moment."

First half of this is germane to this thread and I find it's true for me:

http://gossamergear.com/wp/tribal/how-to-go-lighter/shave-a-few-more-grams

Alessandra,

For a liner – I would definitely take one. Very useful in hostels, couches, floors of people so kind to let you crash there – the Cocoon Expedition Liner is I think the smallest, lightest liner out there at 120gr. The regular (no.2) size would fit you well (I'm 184cm, which is roughly same length as you if I remember correctly).

In your shoes I would personally combine that with a Katabatic Gear Palisade quilt, or similar bag (the quilt saves some weight). I would add a thinner quilt over that for the periods you would need it. You would have to organise having it send to you, or send it along yourself – but that would be better than carrying a too warm system. Alternatively, when in hotter climates you can just take the thinner quilt and send out the rest.

If too expensive – you could take a 10˚C synth quilt like the Prodigy 50 for a very reasonable $155.
If that is too expensive a member here who is good at making things himself offered to make one for cheaper, see near bottom of this thread:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=91325&disable_pagination=1

" i could make you a simple, no thrills Summer (50 degree) Apex quilt for very reasonable. If no bells and whistles, it would cost about half of what a Prodigy quilt would (not including the shipping). I have no idea what shipping from the U.S. to Japan is like though.
If interested you can email me at justin.whitson10 at gmail dot com"

I hope it's not out of line in me posting that here, but you could contact Justing Whitson to see if he could make you a cheaper alternative.

Hope that helps, have fun on your trip.

Ian,.
If you read the "leave insulation at home" bit from Glen Van Peski and then compare that to what I do , one could think that one of the two has to be wrong.
They are however describing two different situations.
If I were a big mile a day through-hiker (get up, quick breakfast , early take off then late arrival at camp, quick dinner and in bed) the GVP version can work very well and makes a lot of sense.
However if you take your time in the morning and may arrive early in the afternoon or even spend a day or two at camp, the idea of wrapping a quilt around you to keep warm will get old very fast.
BTW, note that Glen is into SUL not something that I would suggest to a novice (nor to the ones that are into comfort like me…)
Of course I don't know exactly what Allessandra will do and possibly neither style will work for her , just a different way of looking at the same thing.

You will find EN ratings to be accurate within their parameters. They use a pad, thick wool socks and long johns (and a balaclava?) on the test dummy. You can look at this as taking the numbers and adding 5-10F to them.

While liners may add a bit, 5-8F, that is not their big job. They are designed more to keep a sleeping bag clean. I find them annoying.

Like Franco says, GVP is a SULer. while it is true that insulation is best spent in a bag, you cannot ignore the down jacket. At tis point I would disagree with him. I rarely hike for more than 10 hours. Usually closer to 6 or 8. Getting up in the morning is often a cold, frozen affair. Dew, ice and cold weather conspire to make my morning oatmeal (Marco's Mud) taste delicious. Warm, and steamy as I sit under my bag with my jacket on listening to a bird. When i get to camp, it is often the first thing I put on, after getting out of my hiking shirt (often soaked with sweat.) I use it about 12 hours per day, including sleeping. The ADK's can be cold, even in summer. A jacket is an essential part of my base weight, along with rain gear and a tarp. The second part of staying warm, perhaps equally important, is being wet. Down can fail if it gets wet. A jacket is much more versitile than extra insulation in a bag, even if it weighs ~4-5 ounces more (discounting the down which could have been added to the bag.)

But, long johns, wool socks and my jacket will only take my sleeping system down about 10F. I have been out to 25F, but it was cool, not really comfortable. My base load is about 8 pounds. I don't carry a lot of clothing. 2 pair of socks, jacket, long johns, lightweight fleece pullover, rain jacket. At 32F, in the ADK mountain mist, I may need all of it. In Peru, you will need more. Don't go so very light you skip a bit of extra insulation.

Generally, I have found that you cannot extend a bag much beyond 10-15F. you will have some cold spots. Extra internal insulation (a jacket) only works as long as it has room to loft. Thicker materials, or more layers will stretch the fabric removing loft. so making it warmer with multiple layers often doesn't work. A liner, long johns and a jacket, for instance, is about the max you can use in a bag, or, about 10F. A quilt is a bit better in this regard, but, you may get more drafts.

liners may add a bit, 5-8F

Comparing WM Ultralite to Summerlite, similar dimensions, rated at 20 and 32, respectively, I see the former has 7oz more down. Why don't they just sew in one of these 4oz liners instead of half that extra down?

I'm wondering whether you even bother to read the responses in all the threads you've started on this subject…

I suggested a 20deg down sleeping bag plus summer-weight synthetic quilt as a sleep system in one of your other threads. For 3lb, it would cover most of the temp range you want plus give you some flexibility for warmer conditions, give you a back-up in case one or the other gets damaged, wet or needs cleaning.

If you're concerned about budget, here's a decent solution:
700-fill, DriDown, EN-rated to 23deg, 2lb 1oz sleeping bag for $173:
http://www.campsaver.com/sierra-designs-zissou-30-sleeping-bag

PLUS Enlightened Equipment's 2.1oz Apex 'Prodigy' summer quilt, 14oz total, $155:
http://store.enlightenedequipment.com/prodigy/

Thermarest Women's ProLite Plus sleeping pad, RValue 4.6, 21oz, $83:
http://www.rei.com/product/829823/therm-a-rest-prolite-plus-sleeping-pad-womens-#specsTab

Hi Franco,

I should have been clearer. If I were taking on a cross South America adventure, I'd certainly bring insulation to wear as I would expect to see temperatures below 20* when hiking. For me, this is about the threshold of where I need to wear something more than a shell when I'm moving or taking more than a short break. Since I'd have to bring this insulation anyways, it'd be foolish not to incorporate it into my sleep system.

The point I was trying to make is, don't carry extra insulation that will only be used when sleeping. In my opinion, the money and weight penalty would be better spent on extra down for the sleeping bag.

Just my opinion.

"The point I was trying to make is, don't carry extra insulation that will only be used when sleeping. In my opinion, the money and weight penalty would be better spent on extra down for the sleeping bag. "

+1

A couple of extra ounces of down in a bag will be a better cost and weight savings versus puffy clothes just for sleeping.

Ian
I thought that I made the point that those puffy layers are the same as I wear at camp very clear…

Anyway one thing that I forgot to mention is that when getting close to freezing and below I switch from a Neo Air to an Exped DM7.
On top of a Neo Air with the layering system I outlined I would be cold .
So this is a good place to add that even if I used an Ultralite (I have that) and my layering system on a Neo Air I would still be cold as I would be and more so on top of a Z Lite.
I have used the Neo Air on snow but on top of my version of a Z Lite not by itself (after the first time…)
That home made Z Lite plus Z Lite is OK but not as comfortable as the DM7 alone.

Looking at that photo reminded me of my mate's HGK* waking me up in the morning and a hot cup of coffee appearing at my door shortly after.
Here is another suggestion.
As much as I love my Caldera Cone (alcohol kit) that is NOT what I use if melting snow is required.
It can be done (and I have with a 1.5L version) but takes a lot of time and fuel to do it.
*XGK .
An MSR flame thrower often used as a stove.
(photo by Yair Kellner)

Franco,

You did make your point and we're in agreement. I'm not advocating for the OP to not bring insulation. I'm just suggesting that if she's bringing something for the sole purpose of boosting her sleeping bag warmth (eg fleece pants / 9oz sleeping bag liner) and it's an item she won't wear hiking or in camp, in my opinion, that weight would be better served as extra down in her sleeping bag.

Awesome pic.

The hard part here is that often we forget cricial details (my mat…) or we just take it for granted that "it is understood" when in fact only becomes obvious once you have experienced the situation.

BTW, several of "my best shots" have been taken by Yair. My avatar is also one of his shots.

Sumi, yes I do. Infact, as said in a previous post, I have printed all the threads out and went through them with a pencil. I, though, sometimes get lost or confused with so many technical terms I don't understand and possibly forget some of it too, as my needs change.

Thanks for the advice though, I really appreciate it. I mean it.

Here something that might come handy to others too, in the future (I hope).
I'd like to know your thoughts on the below temperatures, as they don't look particularly accurate to me or something one can refer to, in order to choose the right sleeping system; I might be wrong though. (The countries are in the order I should be visiting them in, starting from Belize at the end of June…).

Cheers,
Alex

^ In reading those charts I am struggling to find the 5F average daily temperatures you have been adamantly insisting you will encounter.

Can you please point out where you got that information?

They are averaging out the lows for each month, and also across cities. This will mean you don’t see the actually lowest numbers. E.g. you can have a few nights a month at 5F, but if the rest of the nights are warmer, the average low will be higher.

For example, running the query “oruro bolivia may 2013 temperatures” on Wolfram Alpha should show a chart with the low around 9F:

https://www.wolframalpha.com/input/?i=oruro+bolivia+may+2013+temperatures

However, if you select the chart option to show the past 5 or 10 years, those lows go away due to the averaging.

As you mentioned Bolivia, in the dry season the trade winds shift and bring occasional arctic winds (surazos) that bring cold air up from Patagonia. This makes for very cold temperatures even though Bolivia is “tropical”. Remember, even though the seasons are reversed, in the tropics it’s more accurate to refer to the rainy season and the dry season rather than “winter” and “summer”.

Ahah, well I'm not sure which altitudes they have taken those temperatures at to be honest, but speaking with friends who travelled in South America, they told me the coldest temperatures they encountered, were in Bolivia (-15C), in Northern Argentina (-10F) and in Sotuhern Argentina (-25F). Then, reading the Global Test Main Page http://www.backpackinglight.com/cgi-bin/backpackinglight/global_test_main_page of that couple's round the world honeymoon's trip, thye say that the coldest temperature they found in SA was -8C…so I'm just going with this data really.

So where can I find an accurate average night temperature per month in each country of Latin America?

Edit to add: I like this website! https://www.wolframalpha.com/input/?i=BOLIVIA+YEARLY+TEMPERATURES

Can I take these averages as reference?

I'm following the Giro D'Italia*.
The temperature at the start yesterday was 29c,sunny.
About half a way into the race it was 14c ,hailing; however not all that far from that , it was snowing.
Putting that " snowing" temp at -3c, using that data the average temperature in the North of Italy at 11 AM was 12c degrees.

The other day here in Melbourne at 2 PM we had 23c , sunny.
My mate was up in the Alps(about 1 cm away on the Aussie map) , 4c at about the same time.
Between the two, we enjoyed a shared temperature of about 13.5 c.
(it felt a warm 13.5 for me , not so much for my mate)

If the above does not make any sense, maybe this will help :

"Bolivia has a high level of biodiversity, considered one of the greatest in the world, as well as several ecoregions with ecological sub-units such as the Altiplano, tropical rainforests (including Amazon rainforest), dry valleys, and the Chiquitania, which is a tropical savanna. These areas feature enormous variations in altitude, from an elevation of 6,542 metres (21,463 ft) above sea level in Nevado Sajama to nearly 70 metres (230 ft) along the Paraguay River. Although a country of great geographic diversity, Bolivia has remained a landlocked country since the War of the Pacific."

BTW, I hope you enjoyed your scoop of chocolate ice cream yesterday. That is why I had two so that on average you would have one too.
*Giro D'Italia , just like the Tour De France but with an Italian accent
Go Cadel!!!!!!!

How the hell do I get to understand which temperatures I'm going to encounter then?! :-)

Do yourself a favor and buy the cheapest 30* bag you can find that will get you through Central America and northern South America. Assuming that there will be some backpacking done along the way, you'll have a better idea of what you'll need once you make it to Bolivia. Once you're there, pick the brains of the locals regarding the historical weather conditions.