I'm looking for some advice on what overnight temperatures we might expect in the Sunshine - Mt. Assiniboine area at the end of July. Wondering if a bag rated to about -2c would normally be adequate?

Thanks!

I will be there for the Aug long weekend. I'm bringing my MEC Raven which is rated to about - 7. If it's not good enough I'll have to find someone to curl up with

It's over 2 weeks away for crying out loud. What's with all of these "what will the weather or temperature be like in 2 or 3 weeks" threads?? Let me get my crystal ball. It's the rockies, it could be anything.

Expect -5C to + 10C. It can snow but that is unusual in late july.

Check http://www.snow-forecast.com/resorts/Sunshine for 6 day forecast freezing level before you go.

Canadian Rockies rule of thumb: Expect snow on every trip. Then if it doesn't, you'll be pleasantly surprised.

Seriously though, expect snow on every trip. The Rockies are very unpredictable. I've carried a -7C bag for years and been fine though. -2C bag might be OK if you're a warm sleeper. Or you could just put on extra layers while you sleep. If you're cold and not wearing all the clothing you brought with you, then you have no right to complain. I've had August long weekends with +30C temperatures and no clouds (2003) and others where it snowed heavily (don't remember which year).

A lot depends on the rest of your gear, too. I've been in the mountains the last couple of weekends, and I've brought my 0° synthetic bag and I've been too warm. However, I've also been camping at lower altitudes, and sharing a small tent with a full fly which warms up pretty quickly and seems to stay warm.

Brilang's right, though. Expect anything, even snow. If I was car camping, I'd have a -10°
down bag in the vehicle, and if I was going backcountry for longer than a day or two, I'd carry it instead of the 0°C bag. The weight's about the same for mine, so the only real difference is the insulating values if the bag gets wet.

Thanks everyone for letting me know what bags you normally use in the area. I'll bring the same stuff I typically use in summer above treeline here in Yukon. A -2c bag and extra layers of clothing are usually good even when it snows.

Thanks

Ooops! 6" of fresh snow in Jasper this morning!

That is a lot of snow on the ground for Jasper given that low of elevation!

Yeah - it can snow on any given day in the summer in the rockies. We were at Aster lake one Aug 1 long weekend day and got almost a foot of snow so be prepared.

I discovered a thin layer of ice had formed overnight on my 1L Nalgene bottle when I awoke in the morning when staying at the Og Lake Campground late July of 2008. I had a "generously rated" -5 celius bag (more like 0 degrees) and I was freezing that night, had to put on all my clothes that night and was still cold. Magog Campground the next two nights was much warmer and more pleasant. So, you never know.

A rule of thumbs Clockwerkz, up the alpine, even during summer peak season in the Rockies, bring the warmest bag you can, you'll never know what might happen and you will be glad if it does. I have 3 bags for different areas: -10C / -7c / 0c and a fleece liner to add 5c of warmth as a back up measure if needed. At sea level during summer months: 0c is ok. Higher up you go, you have to adapt the rating factor.

I should mention, usually, at sea level, the temperature would most likely be as predicted, either raining or sunny. The higher you hike, the changes increase with variations of temperature and weather patterns.

Have a good summer!