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What R-value sleeping pad do you need at 35F?

Updated 2026-09-24 ยท Researched from published specs and verified owner reviews

Quick answerFor a 35F overnight low on the ground, an average sleeper needs a pad of about R 3.5 on the ASTM F3340 scale; on a cot, about R 4.5. Pair it with a bag rated around 25F.
TaskStar 4" Self Inflating Sleeping Pad for Camping with Pillow

TaskStar 4" Self Inflating Sleeping Pad for Camping with Pillow

$49.99

The listing states R 9.5, which covers the R 3.5 a 35F night calls for.

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What R-value do you need at 35F?

35F is three-season territory. The ground pulls heat out of you much faster than air, and your sleeping bag insulation is crushed flat underneath you, so the pad does nearly all the work below you. On the ASTM F3340 scale most brands now use, an average sleeper on a tent floor wants about R 3.5 at this temperature.

R-value for a 35F low by surface and sleeper
Sleeping onWarm sleeperAverageCold sleeper
Tent floorR 3R 3.5R 4.5
CotR 4R 4.5R 5.5
Car cargo floorR 3.5R 4R 5
Air mattressR 4R 4.5R 5.5

Car camping pads for 35F nights

Where a listing states its R-value we show pads that meet this target; otherwise the thick car camping pads in the catalog, so check each listing's stated figure.

What else keeps you warm at 35F?

Around 35F, cots and air mattresses start to feel cold from below. Add a foam pad or a wool blanket on top of either, wear a dry base layer and a hat to bed, and eat something before sleeping.

Sleeping bags for cold nights

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Frequently asked questions

Is an air mattress warm enough at 35F?

Not on its own. A standard air mattress insulates at roughly R 1 or less, and at 35F you want about R 4.5 under you. Lay a foam or self-inflating pad on top of the mattress, under your sleeping bag, to close the gap.

What sleeping bag rating do I need for 35F?

Choose a bag whose comfort rating, or lower limit if that is all the maker lists, is about 25F, roughly 10 degrees under the expected low. The pad and the bag work as a system: a warm bag on a thin pad still sleeps cold, because the insulation underneath you is crushed flat.

Can I stack pads to reach R 3.5?

Yes. R-values add, so a closed-cell foam pad around R 2 under a self-inflating pad around R 1.5 reaches about R 3.5. Put the foam on the bottom to protect the inflatable from punctures.

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Researched guidance, not professional advice. Figures are published specifications or clearly labelled conventions; check your own gear's manual and your campground's rules.