Lindylair's post has me thinking about the relationship between the pad and the sleeping bag for the first few weeks after ice out. Far from a gear junkie, I think of my own equipment more on the lines of gear junk.

So, what is your take on the importance of the pad/bag for warmth?

You need both appropriate for the expected temperatures.

Insulted pad is critical to stay warm when the ground is cold…which it is in the Spring. Cold ground is a heat sink. Simple thermodynamics.

I would say 50/50. CBS cold butt syndrome is not a good thing in the woods. the ground is slowly pulling the heat out of your body.

Gear junkie versus junkie gear...hahaha!

Good question, Nooneuno. I have a slightly better bag than pad but as I think about it perhaps it probably should be reversed. I think the ground can cause you to lose heat faster than the air...right?

I think staying dry is essential and innie/outie has been debated ad nauseam on this site so I won't go there! :)

50/50 is good enough for me though. I use a decent down quilt, a decent pad, and sleep in merino wool on cold nights and have been mostly very comfortable. When my youngest two daughters come with they each use a fleece liner as well.

Is there any research on this? I looked really quick and didn’t find anything but opinions but didn’t look hard.

My take is the colder the ground the more important the pad is. At least 50/50. Warm summer it is alot less important.

I tend to use a higher R value pad form Exped with a 1#ish down bag good down to 35 degrees and have been in 30 degree weather just fine. I am sure with a less R value pad I would not have been comfortable.

T

I just use a foam pad under my sleeping bag. You don’t need much. I am never cold from underneath, always get cold from the top.

I also have a neo-air inflatable pad for comfort. I do take a little extra in my packs for sleeping. If I’m not comfortable at night I might as well just go home.

Tom

In cold weather a good pad is critical. Compressed insulation is virtually no insulation. I had an early April paddle trip that ended with a winter storm and a last night with temps below 10 degrees. I had a 15 degree bag and an Exped Downmat 9 and was toasty warm once my bag was warmed up by my body.

During the previous year (with the same bag) I had a series of nights just below freezing on a spring trip and an insulated Big Agnes pad and simply could not reach a temperature equilibrium that allowed uninterrupted sleep.

Interesting question. Due to individual variation, I don't think I could assign a general ratio.

Best way to know is to try it out right now, assuming you're not somewhere warmer than most of MN and WI currently. It's not going to be much warmer one month from now in the BWCA or Canada.

I guess I approach it like "sleep-number systems": find your backcountry number and dial it in, recognizing the impact of season.

The cold, damp ground of spring time was a primary motivator for learning to use a hammock system. I did what most people do - watched a lot of Shug videos and set up a backyard campsite to test everything in cold / precip / wind conditions. If no backyard, use the state park in early spring.

The past few nights of hanging in the backyard have been 20 - 30 degrees F, in wind, rain, sleet and then snow this morning, pretty much what I envision for Canada in late May. My own sleep-number is two top quilts, a sleeping pad and an underquilt. That's in addition to a down skullcap, merino layers, some puffy pants and mittens.
Others posting here would roast in that set-up.

Banksiana: "In cold weather a good pad is critical. Compressed insulation is virtually no insulation. I had an early April paddle trip that ended with a winter storm and a last night with temps below 10 degrees. I had a 15 degree bag and an Exped Downmat 9 and was toasty warm once my bag was warmed up by my body.


During the previous year (with the same bag) I had a series of nights just below freezing on a spring trip and an insulated Big Agnes pad and simply could not reach a temperature equilibrium that allowed uninterrupted sleep."

+1

60/40 at least. On fall trips, I'll often find myself uncovering an arm for some relief from the warmth, but heaven help me if it winds up off of the pad and out on the cold tent floor.

Lots of good comments. Jillpine mentioned a sleeping hat which is a requirement in my sleep system. Also, remember to fluff your sleeping bag each night. I have one bag where the down migrates from the top to the bottom so I shake it from the backside for extra down on top. 50/50

plander: "Insulted pad is critical to stay warm when the ground is cold…which it is in the Spring. Cold ground is a heat sink. Simple thermodynamics. "

This looks interesting...I am definitely going to try this. I just told my Therm-A-Rest that its mother is a hamster and its father smelled of elderberries.

For warmth, if I had to put a number to it I’d say 60% bag and 40% pad. In the spring when the ice is just going out, the water may be 32° or so, but the ground has likely started to warm from the sun getting higher and few leaves on trees. So maybe it’s 40-50° or so (guessing, never measured yet). That will vary significantly by location, but it’s still plenty cold to lose heat via conduction. The air around you will likely be colder at night. That said, I agree with Tumblehome that it may not take too much to provide insulation under you. I have an Exped Downmat 7 LW which has I think an R value of 5.8, and that’s probably more than I need for paddling trips. On mid summer trips I wish it was less. On winter camping trips where I sleep on packed snow, I use the same pad but add a Thermorest Zlite which is R=2.0, and that’s been enough down to -30° or so. R values are additive, so adding a closed cell pad like the Zlite is an option to get more warmth from a not so well insulated pad.

Of course, it looks like everyone so far has responded thinking of warmth, not general comfort which also matters. I definitely started sleeping better on my 2.5 inch Exped over my old 1 inch self-inflating pad.

50/50 which is why I hang on to my Exped Downmat 9. and 2 other insulated but lower R value pads.

butthead

If you were buying a winter parka would you prefer 50/50 or 80/20 . . . ?

Get all the insulation under you that you can: try to go for a realistic R5 or better. A couple foam pads is ok but that's probably about R4. When the ground is actually warm just sleep on whatever has enough padding.

I learned the hard way, not realizing how I was being chilled with insufficient foam and air pads until I upgraded. Too much weight carried with warm clothes at night when the problem was insulation under me.

How you sleep is a factor also. If you don't move around much an insulated inflatable pad is fine. If you are like me you flip, flop and squirm all night long and roll off the pad onto the cold ground. I switched to a 25" foam Ridgerest pad and a 1/2 length foam pad under my hips and shoulders, along with an extra wide 20 degree down bag. I still end up with an arm or leg on the ground sometimes but warm up quick once I'm back on the mats. A decent pillow that insulate your head is a big help too.
The 2 pads only weigh 1.5# but are bulky.

In 2019 my son wanted to take a trip mid May when he graduated, so we took a trip. The weather was in the mid to upper 40's maybe low 50's during the day but was below freezing every night. We had a zero degree and a 15 degree bag with us, but we had cheaper 1" pads. We froze our butts off. That is when I was convinced that you have to have a good pad to go with a good bag. I'd say its 50/50

Lord help us......another Monty Python Fan !

plander: "Insulted pad is critical to stay warm when the ground is cold…which it is in the Spring. Cold ground is a heat sink. Simple thermodynamics. "

Very True

Just thought I would let you guys know I threw down on an Exped Ultra 3R after reading your thoughts. Never been a cold sleeper, but thinking more of comfort having used a Thermarest 1” for so many years. Thinking this will be an upgrade certainly worth it. Should be a nice addition to my new tent and can’t wait to try out the new gear. Thanks a million for being a great resource of info.
Cheers, scat

50/50 Pad is equally important.

Off-topic but worth a mention: A Helinox cot one is a game-changer for lifting off the cold ground. The wider version is best as I discovered that my arms will flop off the sides with the cot lite version--if I lay on my back. The cot lite version is 2.13 lbs and the wider cot one is 5 lbs. Strong & taught surface design. Far fewer joint and muscle aches. It's pricey but compare the price to high-quality sleep bags & pads combined.

I like using my cot as it keeps me off the ground. Place your inflated pad on the cot and use bungy cords around cot and pad at your feet area to keep the pad from slipping or sliding off the cot. Take a good sleeping bag and you should be OK. I take an insulated bag if it would be needed. Always use some kind of head covering in cool weather or cold weather. Stocking hat. Keeping warm is of paramount importance for a good trip.