The skyline of Cairo was barely visible as dust blown in from the surrounding desert hung in the air and shrouded the Egyptian capital for a second day.
A few incoming flights were diverted to other airports in the country but most air traffic was normal, an airport official said.
But the Suez Canal southeast of Cairo was closed, with 52 ships waiting to enter from the Red Sea as winds reached 74 kilometres (46 miles) per hour, officials told AFP.
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Traffic would resume from 2000 GMT Wednesday, the officials said, with 35 vessels due to pass and the remainder on Thursday.
Another 26 vessels were stranded in the Mediterranean at the northern entrance to the canal, but it was unclear when they would pass, officials said.
The health ministry advised Egyptians to wear masks when leaving their homes.
In neighbouring Israel, the domestic carrier Arkia said it had grounded flights for several hours until 1400 GMT because of bad weather.