How do I keep a tent cool in hot weather?

The universal experience of hot-weather camping is being driven out of the tent by seven in the morning. That is because a tent has essentially no insulation and no thermal mass — as soon as the sun strikes the flysheet it heats within minutes, and there is nothing to slow it. Everything that helps is either about intercepting the sun or moving air, and most of it is decided when you choose where to pitch.

Safety

Step by step

1. Choose the pitch for morning shade, not afternoon shade.This is the single most valuable decision. By late afternoon you are outside anyway; it is the early sun that ends your sleep. Work out where the sun rises and find something — a tree, a hedge, a building, a hillside — that will shade the tent from first light until mid-morning. A pitch that is lovely and shaded at six in the evening may be in full sun at six in the morning.
2. Orient the tent to the breeze.Point the largest openings — the doors and the big mesh panels — into the prevailing wind so air is driven through the tent rather than around it. Pitching with the back to the breeze is right for a storm and wrong for a heatwave, and it is worth deciding deliberately which problem you are solving.
3. Look for a pitch with airflow rather than a sheltered hollow.Sheltered corners, hedged enclosures and dips are still and stuffy in hot weather, and they collect damp air overnight. Slightly exposed, slightly higher ground is cooler and drier, and it reduces condensation as well.
4. Open everything before the sun arrives.The same principle as a house. Once the tent is hot, opening it up achieves relatively little because the air outside is warming too. Vents, doors and windows open from first light, or left open overnight, is what keeps it liveable.
5. Take the inner tent down or roll the sides during the day.Most tents are far more usable in heat with the inner removed or the sides rolled up, leaving a shaded flysheet canopy with air moving underneath. Shade plus airflow is a pleasant place to sit; a closed inner tent is not.
6. Add a tarp above the flysheet if you can.A separate tarp rigged a little above the tent, with an air gap between, is dramatically effective — it intercepts the radiation before it reaches the flysheet and the gap lets the heat carry away. This is the single best piece of equipment for hot-weather camping, and a light-coloured one is better than a dark one.
7. Use a battery fan for still nights.A small rechargeable fan hung in the apex makes a real difference on a still night, both for temperature and for reducing condensation. It uses very little power and it is the difference between sleeping and not.
8. Sleep with less insulation underneath.Sleeping mats are designed to insulate you from cold ground, which is exactly wrong in a heatwave. A thinner mat, or a camp bed that lets air circulate underneath, sleeps considerably cooler. A sleeping bag liner alone often beats a bag.
9. Keep the porch clear and shaded.A porch full of kit in the sun radiates into the inner tent. Keeping gear shaded, and the porch open, helps more than it sounds. Store anything heat-sensitive — electronics, batteries, gas canisters, sun cream, medicines — in shade outside rather than inside a hot tent.
10. Plan the day around the tent rather than the reverse.The realistic answer is that a tent is a night shelter in a heatwave. Be out of it in the middle of the day, take shade with you, and come back when it cools. Fighting to make a tent comfortable at two in the afternoon is not a winnable battle.

Tips

• A light-coloured or silvered tarp above the tent outperforms every other measure. The air gap between tarp and flysheet is what makes it work — a tarp laid on the tent is much less effective.
• Groundsheets on grass are cooler than on sand, gravel or a hardstanding pitch, which store and radiate heat well into the evening.
• Check whether the site allows you to move pitch. Many will let you switch if the one you were given is in full sun, and it costs nothing to ask.
• Cool box guidance matters more when camping than anywhere else — that has its own guide, and it is worth reading before a hot trip rather than after.
• Condensation in the morning is a separate problem with its own guide, and the ventilation that keeps a tent cool also happens to reduce it.

Common mistakes

• Choosing the pitch for afternoon shade — It is the early morning sun that makes a tent unbearable and ends your sleep. Shade from first light to mid-morning is what matters.
• Pitching in a sheltered hollow — Still air is stuffy and hot and collects damp overnight. Slightly exposed higher ground is cooler, drier and more comfortable.
• Waiting until the tent is hot before opening it — By then the outside air is warming too and there is little left to gain. Open the vents from first light or leave them open overnight.
• Taking a barbecue or stove into the tent or porch — Carbon monoxide from cooling charcoal or a burning stove is odourless and kills campers every year. Nothing that burns goes inside, including after cooking.
• Using a thick insulated sleeping mat in a heatwave — It is designed to stop heat escaping into the ground, which is the opposite of what you want. A thin mat or a camp bed with airflow underneath is far cooler.

Questions people ask