a substantial amount of wind is also caused by (differential) solar heating: that's why wind doesn't only go in one direction if you've ever spent time at the

a substantial amount of wind is also caused by (differential) solar heating: that's why wind doesn't only go in one direction if you've ever spent time at the seashore, the wind comes in off the sea during the day (because of rising thermals on the land side) and blows back offshore at night (because the land cools and the sea is now warmer) that time in between the air is dead-still, and that's when the swarms of gnats can find you.