Sydney has seen some impressive rainfall over the last couple of days, but how does it stack up against previous month and years. 

A low pressure system and associated trough that have been slowly moving across NSW in recent days have delivered some notable rainfall to the Sydney area. 

In the 24 hours from 9am Thursday morning, 44.4mm was recorded at Sydney’s Observatory Hill, making it the best daily rainfall since mid-March when 54.6mm fell in 24 hours. With rainfall continuing through Friday and into Saturday morning, a further 29.4mm was recorded in the 24 hours from 9am Friday. 

This combined total of just shy of 74mm makes it the wettest pair of days for the city since early June 2017, when nearly 166mm fell in the rain gauge. 

Looking at October as alone, this month has been the wettest October since 2014 (87mm), with 75.6mm recorded already, including the 2.2mm that fell in the 24 hours from 9am Wednesday. 

If by the months end more than 87mm has been recorded at Observatory Hill, it will be the wettest October since 2009 when a massive 180mm fell, more than double the monthly average. 

With showers expected on and off for the next week, and more than half the month left, a further 10-15mm of rainfall isn’t unrealistic.

– By Thomas Hough, Weatherzone.com.au