Climate of Mawson

Temperature

Mean daily maximum temperatures at Mawson is around 3 °C in January, and around -16 °C in August. Mean daily minimum temperatures range from around -3 °C in January to around -21 °C from July to September.

The highest temperature recorded is 11 °C, in January and the lowest is -36 °C, in July.

Wind

The katabatic wind is dominant, with the wind coming from between east and southeast over 65 percent of the time. Mean daily wind speed is almost 40 km/h. The strongest gust recorded was 248 km/h.

Snow

Snowfalls are much less frequent than at either Casey or Davis. Falls are most common during December and January when they can be expected to occur on 7 days each month; in other months it averages 4 or 5 days. As with other Antarctic locations in strong wind areas precipitation is hard to quantify. On a few very rare occasions rain has fallen at Mawson, resulting usually in a short-lived glaze or rime covering the exposed rock.

Cloud and visibility

Mean cloudiness throughout the year averages five-eighths. The frequency of clear days is somewhat higher in winter than in midsummer, when the retreat of sea ice brings the station under more maritime conditions.

Fog is rare at Mawson but is observed frequently in summer in coastal waters beyond the range of offshore katabatic winds. Visibility is usually good except in the presence of drifting snow, which peaks in late winter (10 days a month), decreasing in midsummer to about 1 day a month. Availability of snow affects frequency of drifting snow occurrence; frequently the catchment area of the wind system is exhausted of unconsolidated snow and conditions will remain clear despite strong winds, especially in summer. White-out occurs fairly frequently, but because of the existence of a number of exposed rock areas, distant mountains and islands the effect on human perception is not as marked as in completely snow and ice covered terrain.

Sea Ice

The extent of pack ice on average reaches as far north as latitude 58 °S in October, but less frequently than one year in five the northern limit of pack ice can be found nearer 57 °S. Fast ice attains its greatest extent in September when the fast ice edge can be up to 100 km north of Mawson. The average yearly maximum thickness of fast ice (including snow cover) near Mawson is about 1.6 metres, usually in October. The greatest fast ice thickness (including snow cover) measured near Mawson is 1.9 metres. Fast ice breaks up and is carried out to sea, usually in January.

Last updated on 22 June 2004