Sleeping Bags - Season question

Southpaw

Hi

I'm looking to buy a new sleeping bag. But I don't understand the season ratings. Some are 2 season some are 3 season. Am I right in thinking 2 season is summer/spring and 3 is summer/spring/autumn??

I am after a bag which will be waterproof as I intend sleeping outside without a tent. Do I therefore need a 4 season bag??

Thanks in advance.
This may be a stupid question but at the moment I don't know the answer.:o

Sparkly

it's not a stupid question but the answer isn't straightforward either. The season rating is 1-5, the higher the rating, the lower the recommended temperature you can use a sleeping bag, but they are only guidelines as each person is different, and each bag maker may use different rules to get the rating. .
1 = summer = approx +5 degrees centigrade
2=spring&summer = 0 C
3 = spring to autumn = -5 C
4 = winter = -10 C
5 = expedition - 15 C
There's a newer rating system which is an official standard and bags should be rated against a standard test. This is where it gets a bit complicated.
Comfort - lowest temperature at which a standard WOMAN would have a comfortable nights sleep, lying on her back and relaxed.
Lower Limit - lowest temperature at which a standard MAN in a rolled up body posture would have a comfortable nights sleep.
Extreme - temperature below which a standard WOMAN could expect strong sensation of cold and maybe actual physical injury from cold (e.g. frost bite or hypothermia).
so the bag will show all 3 ratings, but with different temperatures for each. Mine shows +7C for comfort, +2C for limit and -13C for Extreme.
Waterproofing is different and not related to temperature rating. Some bags can be water repellent for condensation and a bit of damp, and you can also do this with a product likeNikwax, but fully waterproof bags are very not common and very expensive (£300+?) The cheap way to waterproof a bag is to put it inside a plastic sack (bivi bag) but it's not much fun sleeping in one as you sweat like silly and of course your head is usually uncovered anyway. As a minimum, you'll need a plastic sheet or pad to go under the bag if you camp outside a temp so ground damp doesn't penetrate.Then hope it doesn't rain!

Southpaw

Thanks Sparkly.

Sleeping Bag inside a couple of bin bags is what I'd used in the past. Just wondered whether waterproof sleeping bags were widely availiable seems they are too expensive.

Thanks again.

jammiev

Southpaw wrote: »

Hi

I'm looking to buy a new sleeping bag. But I don't understand the season ratings. Some are 2 season some are 3 season. Am I right in thinking 2 season is summer/spring and 3 is summer/spring/autumn??

I am after a bag which will be waterproof as I intend sleeping outside without a tent. Do I therefore need a 4 season bag??

Thanks in advance.
This may be a stupid question but at the moment I don't know the answer.:o

when and where are you sleeping outside?
you can get the orange survival bags to sleep in , protect from cold and rain. if heavy rain you will have to crawl in it a bit to keep head dry and so may sweat a bit!
so idealy a gortex bivy bag would be ideal!
try army surplus shops etc..