Hammock Underquilts and Winter Tarps: How to Stay Warm on Cold Nights

Hammock camping is wonderfully comfortable, right up until the night gets cold. Many first-time hammock campers climb in with a warm sleeping bag and still wake up with a chilly back. The fix isn’t a thicker bag. It’s insulating underneath you and blocking the wind above. That means an underquilt and a good tarp.

Why you get cold in a hammock

Sleeping bag insulation works by trapping warm air in its loft. When you lie in a hammock, your body weight crushes the insulation underneath you flat, so it barely insulates at all. On the ground, a sleeping pad solves this. In a hammock, cool air moves freely underneath, pulling heat from your back and hips. Hammock campers often call this “cold butt syndrome.”

What an underquilt does

An underquilt is a quilt that hangs on the outside of your hammock, cradling its underside. Because nothing presses on it, its insulation keeps its full loft and traps a layer of warm air beneath you. Underquilts like the Chill Gorilla full-length model run from head to toe. They clip or tie to the hammock’s ends, and shock cords snug them close to the hammock body.

Full-length vs. three-quarter length

• Full-length underquilts cover you from shoulders to feet. They’re simpler and warmer, and the usual choice for cold-weather trips.
• Three-quarter (or “torso”) underquilts save weight and pack size. You put a small sit pad or your backpack under your feet to cover the gap.

Getting a good fit

The most common underquilt problem is gaps. If the quilt hangs too low, cold air slips between it and the hammock. If it’s pulled too tight, it compresses and loses warmth. Adjust the suspension until the quilt touches the hammock lightly all the way along, then get in and check again, because your weight changes the shape. Pay special attention to your shoulders, where drafts tend to sneak in.

Pair it with a top quilt

With an underquilt handling your back, many hammockers swap their mummy bag for a top quilt, or simply unzip a sleeping bag and use it like a blanket. It’s easier to get in and out of, and you’re not wrestling a zipper in a narrow hammock. A fleece liner adds a little warmth on shoulder-season nights.

Choosing a tarp for cold or wet weather

Insulation stops heat loss from below. A tarp stops wind, rain and snow from above. In summer, a small diamond or hex tarp may be enough. For colder weather, more coverage helps.

Asymmetric tarps

An asymmetric tarp matches the diagonal lay of a hammock. Many people lie at an angle in a gathered-end hammock to get flatter. One example is the Simply Light Designs asymmetric tarp, rigged head-left and feet-right. Asymmetric tarps give good coverage for very little weight, which makes them popular with ultralight hikers.

Winter tarps

Winter tarps are larger and often have “doors” that close the ends, turning the tarp into a small shelter that blocks wind and blowing snow. Look for:

• A long ridgeline, so the tarp extends well past both ends of the hammock
• Plenty of tie-outs, ideally with reinforced points or D-rings at ground level, so you can pitch low in storms
• Light, weatherproof fabric such as silpoly, which tends to stay taut when it gets wet or cold

Pitching for warmth

In cold or windy weather, pitch the tarp lower and closer to the hammock, and angle one side into the wind. Snow sliding off the tarp is a good sign. Snow piling up means the pitch is too flat. Keep an eye on condensation, though. Leave a little airflow at the ends so moisture can escape.

Quick cold-night hammock checklist

• Underquilt adjusted with no gaps, especially at the shoulders
• Top quilt or unzipped sleeping bag rated for the expected low
• Tarp pitched low with doors or ends closed against the wind
• Warm hat, dry socks and a midlayer to sleep in
• A hot drink before bed and a snack to fuel your body overnight

New to hanging? Start with whether hammock camping is right for you, then dial in your setup with our guide to getting the most out of your camping hammock.

FAQ

Can I just use a sleeping pad in my hammock instead?

You can, and it’s cheaper. But pads slide around, can feel sweaty, and don’t wrap your shoulders. Many people start with a pad and switch to an underquilt for comfort.

How warm an underquilt do I need?

Pick one rated for the lowest temperature you expect, then add a little margin. Wind and damp make nights feel colder than the thermometer suggests.

Do I still need a tarp if there’s no rain in the forecast?

In cold weather, yes. A tarp blocks wind and frost and keeps dew off your quilts, which helps them stay warm.

Is a used underquilt a good buy?

It can be, if it’s clean, still lofts well and has intact shock cords and attachment points. Ask how it was stored, because quilts kept compressed for long periods may lose some loft.