Isle Royale Forums

How accurate is this chart from weathersparks.com. We are planning an August 2024 visit and I’m thinking it is telling me a 35° bag will be fine.

It's probably an average or extrapolation of mainland observations. But IR is sitting in the middle of a huge cold lake and the weather varies greatly, both day to day and depending on where you are on the island--you can have sunny 80s on the ridge and foggy 50s a couple miles away on the shore at the same time. Most experienced folks will take a 20 deg or warmer bag any time of the summer. I've seen upper 30s on the shore at night with the wind blowing off the lake in July. I used to take a 35 deg bag with a silk liner and was OK, but had some less than comfy nights with my base layer on as well. My newer 20 deg bag that I take now is more comfortable. So you're probably OK with the 35 deg bag, but could regret it, so I'd bring a warmer one if you have the option.

I usually bring a 30 degree quilt no matter the time of year (and 0 degree in spring). But that's because I know I'm a very cold sleeper. You know yourself best, and whether a 35 degree bag will be enough for you in the situations Ingo described.

I usually bring a lighter quilt and heavier liner. Then i plan on wearing base layers or more, as needed. In the spring, I will bring a warmer bag because i have been there for many nights below freezing. I agree with dcclark that this is very dependent on the individual,

“Fine” is relative. Are you a warm sleeper, a cold sleeper? Also, that chart doesn’t say where those temperatures are measured. Interior campgrounds tend to be warmer than Lake Superior shoreline campgrounds. Also, be sure to have good insulation underneath you, as well as your sleeping bag. I carry a warmer sleeping bag and mat, because I sleep really cold.

Aug '22 I wore everything I had (wool T, wool long sleeve, fleece, puffy, & raincoat) one night at Moskey...and I was still chilled.

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Yankee Dog wrote: ↑Tue Dec 05, 2023 10:47 pm How accurate is this chart from weathersparks.com. We are planning an August 2024 visit and I’m thinking it is telling me a 35° bag will be fine.

I am a cold sleeper; I don't like to be cold at all. So, I always rock a 32* sleeping bag, regardless of the month. That has always suited me just fine for the past 22 years.

fonixmunkee wrote: ↑Thu May 30, 2024 8:03 pm

Yankee Dog wrote: ↑Tue Dec 05, 2023 10:47 pm How accurate is this chart from weathersparks.com. We are planning an August 2024 visit and I’m thinking it is telling me a 35° bag will be fine.

I am a cold sleeper; I don't like to be cold at all. So, I always rock a 32* sleeping bag, regardless of the month. That has always suited me just fine for the past 22 years.

Same experience here. Nowadays I have a "summer" quilt (32 degrees) and a "spring/fall" quilt (0 degrees). I brought the 0 degree quilt last May and was glad I did.