Cyclone Herbie developed to the northwest of Cocos Island on 18 May before changing structure, rapidly accelerating to the southeast on 21 May, and passing over Denham in the early morning where wind speeds were recorded at 120 kilometres per hour.

Herbie caused structural damage along the coast from Carnarvon to Denham. Further north at Cape Cuvier, the Korean Star, a 30,000 tonne freighter, was wrecked. A two-metre storm surge at Denham inundated the foreshore and several fishing vessels were stranded along the main street when water levels subsided.

As the cyclone moved inland, severe dust storms occurred on its northern side. By contrast, rainfall totals greater than 100 millimetres caused flooding. The Greenough and Irwin Rivers burst their banks flooding houses, especially in Dongara.

The Insurance Council of Australia estimated the 1988 damage at $20 million with the 2011 estimated normalised cost of $117 million.