The northern part of the state, characterised by Monsoonal circulation, in the winter months from May to September is of generally warm dry offshore winds, drawn across the Inter-Tropical Convergence Zone by the low pressure systems of Monsoon Asia. In summer, from November to March, with the displacement of the Intertropical Convergence over northern Australia, the weather is characterised by humid tropical onshore airflows, coupled with thunderstorms and an occasional cyclone, these weather patterns bringing the bulk of the rainfall of the region. The highest wind-gust recorded on the Australian mainland was 259 km/h at Mardi during tropical cyclone Trixie, in 1975 and Whim Creek has the record for the highest rainfall, at 747 mm in 24 hours, associated with a cyclone in 1898.