The dust cloud started in Tucson Tuesday night and swept across the desert before slamming into Phoenix.
Not only did it cut visibility, it also knocked out power to thousands of residents and reduced traffic to a crawl. The wall of dust was accompanied by high winds that ripped up trees, tossed around lawn furniture and caused hazardous driving conditions.
Flights from Los Angeles and Las Vegas to Phoenix were delayed until about 9 p.m.
The National Weather Service in Phoenix said there's a slight chance of thunderstorms Wednesday evening including blowing dust.