Frustrated passengers have received an apology from Qantas after they were forced to sleep at Geraldton Airport overnight, rather than flying to Perth.

Heavy fog caused chaos for nearly half a dozen flights, two of which were forced to land at Geraldton but couldn't leave because the crew had clocked too many hours.

Meanwhile, three other flights from Canberra, Adelaide and Port Hedland were also diverted to airports across WA but did manage to get to Perth.

One customer who slept at Geraldton, Kim, told Gareth Parker on 6PR Breakfast that passengers slept on the floor at the airport in six-degree weather and lashed Qantas over its lack of communication.