At the height of summer, day time temperatures at Casey sometimes rise above freezing. From April to October they fall into the minus 20s and 30s. Temperature extremes recorded at Casey are −41°C in July and +9°C in January.

The yearly average wind speed at Casey is around 20 km/h. In comparison, the yearly average of Hobart in Tasmania is around 12 km/h. Blizzards produced by low pressure systems can strike with little warning and wind gusts well over 250 km/h have been recorded.

The hours of daylight experienced at Casey vary markedly throughout the year. In January the sun stays above the horizon almost continuously. In June, the sun appears for less than an hour each day.

Tidal predictions

Tides are measured for many different research and operational purposes. These measurements have a practical value in working out sea level for mapping elevations and ocean depths, tidal predictions for shipping, and in the calibration of satellite altimeters.

Tide measurements also have a research value. Sea level data helps us understand long-term climate change as well as continental readjustment, heat transfer across the continental shelf, and other oceanographic phenomena including observation of Southern Ocean oscillation.