Strong winds can damage roofing, fences, and signs, and can blow down trees. Previous events have resulted in closure of airports, power lines being brought down, and electrical sparks igniting fires.

Strong winds can occur under a number of different atmospheric conditions, including:

North-west winds: These can occur when a deep trough advancing across the Tasman Sea is squeezed against an intense blocking anticyclone to the east of the South Island. A very strong pressure gradient develops between these two features, resulting in strong winds from the northwest. Such windstorms can last for 6-12 hours.

Southerly gusts: Extreme wind gusts, but of a shorter duration can occur with a sudden change to a southerly air flow. These events are associated with a rapid progression of cold air up the eastern coast of the South Island. They tend to be of short duration, lasting less than one hour.

Wind information in the Otago Natural Hazards Database is mapped at a regional level, and as such detailed variations in wind speed cannot be shown. The wind hazard map shows average annual (January to December) maximum wind speed (km/hr) at 10 m above the ground over tussock or rough grass for the period 1970-2001.