澳大利亚23日遭遇了70年以来最猛烈的沙尘暴袭击，悉尼、堪培拉，以及南部昆士兰州的一些城市均被笼罩在红色沙暴中。澳大利亚卫生部门发出健康警报，要求儿童、老人，以及罹患哮喘和其他呼吸系统疾病的患者待在室内，不要外出。出行的人们都戴着面罩，部分学校关闭，体育活动也被叫停。据悉，此次沙尘源于澳大利亚中部干旱地区，当天悉尼的空气污染程度为平日的1500倍，是迄今为止最高的污染指数纪录。悉尼机场的国内和国际航班均延误3到6小时，部分国际航班因为能见度太低而被取消。

A vast dust storm that blew in from the deserts of Australia's red centre has blanketed the country's largest city and eastern coast in a crimson fog.

A vast dust storm that blew in from the deserts of Australia's red centre has blanketed the country's largest city and eastern coast in a crimson fog, causing widespread traffic chaos and severe flight delays.

Residents from Sydney in New South Wales to Canberra inland and towns in southern Queensland awoke to a red sky and greatly reduced visibility after the country's worst dust storm in 70 years blew in overnight.

The Sydney Harbor Bridge and Opera House were shrouded in the red fog and hundreds of people reported breathing problems to the health authorities.

Children, the elderly and those suffering from asthma or heart or lung diseases were advised to stay indoors as even healthy adults reported "itchy throats" and a metallic aftertaste in their mouths after walking through the thick haze.

Commuters used face masks, originally intended to protect them from the spread of swine flu, to negotiate the clogged streets on their way to work. Some schools were closed and sports activities were called off as the conditions pushed air pollution levels to 1500 times their normal levels – the highest on record.

Passengers at the busy Sydney Airport faced delays of up to six hours for international flights and three hours for domestic trips, and some international flights were cancelled as visibility was reduced to just a few feet.

Sydney ferries were also suspended for several hours for safety reasons.

Cars were cloaked, inches thick, in the orange dust and yachts on the harbor, usually gleaming white, had a dull yellowy sheen.

Locals, ringing in to radio stations to express their shock at the red dawn, compared the quiet streets and general sense of bewilderment to "Armageddon".

"It's like a nuclear winter morning," tourist Peter Wilson, 53, at Circular Quay in central Sydney told Reuters. "It is so eerie." Daniel Hall told the Daily Telegraph that when he awoke in the Sydney suburb of Paddington the sky was "bright red" and "all the cars were covered in dirt".

The atmospheric anomaly, which measured more than 310 miles wide and 620 miles long, was caused by dust clouds blowing east from Australia's dry interior, which has been parched by the worst drought on record. It covered dozens of towns and cities in two states as strong winds snatched up tons of topsoil, threw it high into the sky and carried it hundreds of miles.

The dust hanging over Sydney had largely cleared by midafternoon, although national carrier Qantas said severe delays would last all day because of diverted and late-running flights.

Further north, in the Queensland capital of Brisbane, the sky remained red into the early evening.

The storms visible as a huge brown smudge in satellite photographs of Australia on Wednesday were the most severe since the 1940s, experts said.

"These dust storms are some of the largest in the last 70 years," said Nigel Tapper, an environmental scientist at Monash University. "Ten very dry years over inland southern Australia and very strong westerlies have conspired to produce these storms."