During the height of summer at Casey, day time temperatures occasionally rise above freezing, while from April to October they fall into the minus twenties and thirties. Temperature extremes recorded at Casey are −41°C in July and +9°C in January.
The yearly average wind speed at Casey is around 20km/h. In comparison, Hobart’s yearly average is around 12km/h. However, blizzards produced by low pressure systems strike with little warning and wind gusts well over 250km/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, while in June the sun appears for less than an hour each day.
Tides are measured for many different research and operational purposes. Such measurements have a practical value in determining 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.