The Houston Pilots Association tells Eyewitness News that there are about 40 ships waiting to come into the port.
Another dozen are waiting to leave.
You can monitor ship traffic at marinetraffic.com.
Delayed movement may also have an effect on business. More than 8,000 vessels come through the port every year.
Meanwhile, be careful if you're driving in the fog this morning.
One of the main things to remember is to keep a safe distance from other cars.
Related: How to drive in dense fog
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