Four weeks since fall began, changes showing up

It was close to one-third of the way on Monday from the onset of autumn to the arrival of winter, and even in the golden light of another warm afternoon in Washington, the direction of meteorological movement has become almost noticeable.

Dictated by the tilt of Earth on its axis, and the position of the sun in the sky, autumn arrived in the Northern Hemisphere on Sept. 22, and Monday, Oct. 20, marked the fourth full week since its start.