As reported by the Bureau of Meteorology, February 2007 had a record number of thunderstorms. November to February is traditionally the thunderstorm season in the ACT. On the afternoon of 20 January 2020 a short but severe storm struck Canberra and nearby Queanbeyan in NSW. Hailstones as large as golf-balls and winds over were noted. Many thousands of motor vehicles were badly damaged by hail and many were written off. Over 50,000 insurance claims were lodged, largely for vehicles, and the event was declared a catastrophe by the National Insurance Council. The cost of the storm was over . Power to about 1,000 homes was cut. Sixty-five Commonwealth Scientific and Industrial Research Organisation (CSIRO) experimental greenhouses were severely damaged by hail, and as consequence years of crop, and other types of research, were lost. The Australian Academy of Science's Shine Dome was seriously damaged, with smashed skylights and denting of the copper roof surface. Large numbers of fauna were killed and trees were also damaged. The 1947 Sydney hailstorm was a natural disaster which struck Sydney on 1 January 1947. The storm cell developed on the morning of New Year's Day, a public holiday in Australia, over the Blue Mountains, hitting the city and dissipating east of Bondi in the mid-afternoon. At the time, it was the most severe storm to strike the city since recorded observations began in 1792. On 21 January 1991 severe thunderstorms moved across the northern suburbs of Sydney during the afternoon. Strong winds and large hail stones caused extensive damage. Hail stones up to in diameter and flash flooding was reported in several locations. Some areas received more than of rain in 6 minutes and more than in half an hour. Areas of most severe damage stretched from the Warrawee–Turramurra area to Duffys Forest, with significant damage occurring to property in the Ku-ring-gai, Hornsby and former Warringah council areas. More than 7000 houses were damaged. The total estimated insurance payout for the storm was estimated at 215 million. Australia's most costly natural disaster in dollar terms, , was a severe hail storm over Sydney on 14 April 1999. Hail up to almost the size of cricket balls – circumference – fell in a damage path that extended from Bundeena in the south to Darling Point in the North, and from Sydenham in the inner-west to Bondi Junction in the east. In total, over 20,000 properties and 40,000 vehicles were damaged during the storm with more than 25 aircraft damaged at Sydney Airport.