UKH

I'm heading off to the Pyrenees soon for most of August and sorting out what kit to take. I need to decide which sleeping bag to take for high camps and bivvies and having not been before I don't know how cold it's likely to be.

Presumably warmer than the Alps as its lower and I won't be sleeping on snow or glaciers but how cold might it typically get?

Can I expect the odd night where it dips close to freezing or are hard frosts well below zero the norm etc.

Thanks in advance.

In my experience a 2/3 season sleeping bag has been absolutely fine. (Hope I'm not wrong about this because we're off there too!).  Don't be surprised by the occasional downpour though! Have fun!

Does this mean that even high up, say 2000m+ its not likely to dip below freezing?

Thanks.

https://www.mountain-forecast.com/peaks/Monte-Perdido/forecasts/3355

This may be of some help.

IPP

Take the lightest sleeping bag you have! I was out on a couple of bivvys over the last week. I slept in an 30 year old ME dewline down bag.. it has very little down. I did have a very light tarp with me too. I first went to fhe Pyrenees 20 years ago and took too much heavy kit, including a big sleeping bag. Go light, wear clothes in your bag. It will probably drop to 4 - 6 degrees at 5am but when the sun is up it's hot! 

Well, you've got a lot of range above 2000m and I'm not sure how high up you intend to pitch but yes, in my experience that's very unlikely.  FWIW we'll be taking Mountain Hardwear Phantoms rated -2 which I regard as more than enough (just what we've got) certainly up to 3000m.  I'd take other's advice, go light and leave your jumper on if needs be...

Great, thanks for all the advice, that's settled my decision. I've got a +3 ish rated bag usable to a couple of degrees below if you wear clothes (which I'm happy to do) or a -20 bag which I knew would be overkill but I didn't want to end up shivering my nads off night after night if it routinely dipped to -5 or so.

You might still be too hot.

Think lowest it has got to in last couple of weeks - with rain - is 4c at >3k