The day had been a cloudy one, and the sky had blackened with each succeeding hour of afternoon.

On a Saturday afternoon in September, the western sky blackened and the wind rose.

As I stood waiting, the skies blackened and the heavens opened up, letting fall a really heavy torrent.

The sky blackened, and Channing knew that they were free in space.

It seemed as if the sky had suddenly blackened from the gray gloom of only moments before.

The rain came down harder, and the sky blackened.

By the time I pulled into my lot, the sky had blackened under the cloud cover and a light rain had begun to fall.

The sky blackened, and people pulled their collars up and looked around for shelter.

The sky was blackening, the violet becoming a deep royal purple.

The sky blackens, and I can almost hear rain begin.