Plain English Meaning

The side of the runway the wind is coming from. If the wind is blowing from your left as you face down the runway, the left side is the upwind side.

Full Definition

In an airport traffic pattern, the upwind side is the side of the runway from which the wind is blowing. When entering or flying the pattern, it refers to the area off the side of the runway where the wind originates, as opposed to the downwind side where the wind is going.

Context Anchor

Used when describing airport traffic patterns, especially the position of the upwind leg relative to the runway and wind.

Derivation

Upwind' combines 'up' (toward the source) and 'wind.' Just as 'upstream' means toward the source of a river, 'upwind' means toward the source of the wind. The upwind side of the runway is therefore the side closest to where the wind is coming from.