Sea breezes along the Canterbury coast in the vicinity of Christchurch, New Zealand

Observations are presented suggesting the significance of sea breezes in producing distinctive diurnal boundary layer oscillations over Christchurch. Sea breeze effects are shown to be an all‐year phenomenon reaching their maxima in summer. The interaction of onshore wind components with south‐westerly gradient winds (even under cloudy conditions) appears to produce a distinctive all‐seasons diurnal rhythm in the gradient wind. The development of shallow north‐easterlies blowing into an orographically‐induced lee trough, preceding the onset of ground north‐westerlies, is shown to produce a complicated system of onshore airflow when combined with the sea breeze. Under such conditions it is argued that a sea breeze return current may be discerned. Canterbury sea breezes are an important feature of the local climate and correspond in many respects to classical sea breeze models. Notwithstanding, it is their site‐specific characteristics that render them of particular interest.