A wall of dust that towered over skyscrapers downtown swept across the desert from the south, and KSAZ-TV, a local station, reported it appeared to be roughly 50 miles wide in some spots.
A massive dust storm descended on the Phoenix area on Tuesday night, drastically reducing visibility and delaying flights as strong winds toppled trees and caused power outages for thousands of residents in the valley.
A wall of dust that towered over skyscrapers downtown swept across the desert from the south, and KSAZ-TV, a local station, reported it appeared to be roughly 50 miles (80 kilometres) wide in some spots.
The dust cloud briefly blanketed downtown Phoenix at around nightfall.
The storm was part of the Arizona monsoon season, which typically starts in mid-June and lasts through September 30.
The National Weather Service says strong winds with gusts of more than 60 miles per hour (96 kilometres per hour) rapidly moved the dust cloud northwest through Phoenix and the cities of Avondale, Tempe and Scottsdale.
More than a dozen communities in the area also were placed under a severe thunderstorm watch until 11 p.m. (0600 GMT)
Some 8-thousand utility customers were left without power, KNXV-TV reported late Tuesday.
The Arizona Republic reported winds also downed live wires in Tempe that sparked a fire at a busy intersection, but firefighters were able to quickly extinguish the blaze.
The Federal Aviation Administration said on its website that because of low visibility in the area, no Phoenix-bound flights were allowed to leave Las Vegas or Los Angeles airports until 9 p.m (0400 GMT), and flights at the airport were grounded for about an hour.