| What it is | Waterproof outer tent cover |
| Job | Keep rain out, let inner breathe |
| Forms | A double-wall tent with the body |
| Coverage | Full (best) or partial (lighter) |
A rainfly is the waterproof outer cover of a tent that goes over the tent body to keep out rain while letting the inner tent breathe. Together with the tent body it forms a double-wall tent. A full-coverage rainfly protects best in storms; partial flies save weight but offer less coverage.
How it works
The fly sheds rain while the breathable inner stays drier — the principle of the double-wall tent, which also manages condensation.
Good to know
Skip it only in dry, bug-free weather; with a footprint below, it bookends a tent’s weather protection.
Frequently asked questions
What is a rainfly?
A rainfly is the waterproof outer sheet that goes over a tent's (often mesh) body to keep rain and dew out. The gap between the breathable inner and waterproof fly is what makes a double-wall tent both weatherproof and well-ventilated.
Do you always need the rainfly?
No — in clear, dry, bug-free weather you can leave it off for ventilation and stargazing through a mesh canopy. Put it on whenever rain, heavy dew, wind, or cold is possible, since it provides the tent's weather and warmth protection.
Why does my tent get wet inside even without rain?
Usually condensation: moisture from your breath and body collects on the inside of the fly and can drip. A double-wall tent keeps that moisture off you on the fly, but poor ventilation worsens it — so vent the tent and avoid touching the inner to the wet fly.
Sources
- Tent components — American Hiking Society