But with cooler air sitting tight at ground level, the usual temperature pattern turns upside down for a few hundred feet above the ground.
Known as a temperature inversion, this upside-down pattern acts as a barrier, dividing the cool, calm air on the ground from whatever’s happening above.
On many calm nights, the wind still blows far overhead, but a temperature inversion prevents it from coming down to earth.
At sunrise, everything changes. The sun warms the earth and the lower layers of the atmosphere, mixing everything up.
Without the temperature inversion as a boundary, the winds gust down to the ground again, picking up the most speed on smooth landscapes with little resistance to wind.