Did you know that the Observatory has a weather station?
Sydney Observatory is home to one of the longest continuous weather records in Australia. Weather data has been recorded at Observatory Hill almost every day since July 1858, and the Observatory has long been a hub for the development of Australia’s meteorological network. Weather records are collected from Observatory Hill, between the grounds of the Observatory and Fort Street School site, thereby creating a continuous and comprehensive record of Sydney’s temperature, humidity and rainfall. The contemporary weather station is managed by the Bureau of Meteorology.
What is Meteorology you may ask? It is the study of the Earth’s atmosphere and weather conditions. It can then determine climate trends and patterns and their impact on the environment.
The placement of the Observatory was chosen primarily for astronomical reasons, but its exposure to its wider surroundings was also suitable for recording accurate weather data. William Scott, the Observatory’s first government astronomer remarked that the location ‘occasions some inconvenience in windy weather but on the other hand, there is considerable exemption from smoke and dust, and the building, standing in the midst of a large Government reserve, is not liable to be encroached by neighbouring buildings.’
A barometer was housed inside the Observatory for measuring pressure while an anemometer, a device for recording wind speed, was placed approximately 20 m above the ground, on the Observatory roof. One rain gauge, or pluviometer, was located in the grounds, and another with the anemometer, to measure rainfall. Thermometers were kept on the south side of the Observatory in a thermometer house known as a Glaisher stand, which was common practice at the time. Other instruments within the site measured different variables, such as ground temperatures, sunshine and evaporation.
Over the years, Sydney Observatory has recorded the varied and often wild conditions of Sydney’s weather. The wettest day at the Observatory was during the infamous east-coast low event in 6 August 1986, when over 300 mm fell in just 24 hours. The mercury reached a maximum of 45.8°C on 18 January 2013 during the ‘Angry Summer’ of 2012–2013, when many other extreme temperatures records were broken. The Observatory’s coldest night was back in 22 June 1932, when temperatures fell below 3°C.
Karen Griffiths
Volunteer Program Officer