<P> In February 2010, Sydney received some of the highest rainfalls in 25 years with 65 mm (2.6 in) of rain falling in one night at Observatory Hill . In the first weeks of the month, some suburbs were hit by thunderstorms which brought heavy rain and gusty winds which cut out power and damaged homes . The heavy rain was caused by remnants of ex-tropical Cyclone Olga and humid north - easterly winds feeding into the low pressure trough . 2010 was an overly wet year with the cloudiest October and the third cloudiest July on record . In 2011, Sydney recorded its wettest July since 1950 . The CBD recorded 244 mm (9.61 in) of rain that month . 2011 was also the wettest year since records began in 1858 . </P> <P> On 18 November 2013, a tornado hit Hornsby, a suburb in the Upper North Shore . The tornado's path was 2 km (1.2 mi) long and 50 m (160 ft) wide . The tornado blew off roofs and toppled large trees . The winds in the tornado reached 140 kilometres per hour (87 mph). A total of 12 people were injured in the tornado . </P> <P> On 14 October 2014, a rainstorm described as a "once - in - a-decade event" hit the Sydney region . Parts of Sydney received the heaviest amount of rain in a span of hours in decades . 94 mm (3.70 in) of rain fell in Strathfield in just over three hours . The winds were cyclonic in nature, with Sydney Airport having over 107 km / h (66 mph) gusts, reaching category 1 strength . This event happened due to the formation of an east coast low, which ignited several other low pressure systems . </P> <P> On 20 April 2015, Sydney recorded 119.4 mm (4.70 in) of rainfall, the most in any day since February 2002 . Winds were "cyclonic" in nature, reaching 135 km / h (84 mph). This east coast low was formed with "a really pronounced upper level trough of cold air that had moved in from Victoria", Mr Sharpe said . The maximum temperature was only 15.4 ° C (60 ° F), making it the coldest April day since 1983, according to BOM . </P>

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