Dust storm in Arizona
Media playback is unsupported on your device

Dust storm rolling over Phoenix

11 July 2013 Last updated at 04:26 BST

A dust storm is gathering over farm land in Phoenix, Arizona.

The dust cloud stretches across 16km, seriously limiting visibility in the Pima County area.

Dust storms tend to mark the beginning of the summer thunderstorm season in the south-western United States.