A Lean-To can keep you dry in the wilderness

Lean To
You need a horizontal branch which can be tied between two trees or supported by two branches. Then branches are leaned against the windward side to create an angled roof. The roof can than be covered with branches grass or a tarp if you happen to have one.
The lean-to shelter is probably the simplest and fastest shelter to construct.

Lean To
build a small fire approximately one pace from the front opening. Behind the fire build a reflector wall. This is a short wall which will reflect the heat from the fire back into the shelter. If built properly, this shelter will keep you warm and dry.

Whenever you build a fire near your shelter, remember that natural materials are flammable. Use utmost precaution.