 Rainfall levels in the Riverina are generally low with the median annual rainfall over most of the region between 250 – 500 millimetres ( 9 @.@ 8 – 19 @.@ 7 in ) , rising to between 500 – 800 mm ( 20 – 31 in ) on the eastern fringe . Rain generally falls in the winter in the southern Riverina and around Hay while in the north rainfall patterns are fairly consistent throughout the year . Corowa , in the south eastern Riverina has an average rainfall of 539 @.@ 4 millimetres ( 21 @.@ 2 in ) per year while mean annual rainfall at Hay is 367 @.@ 2 millimetres ( 14 @.@ 5 in ) . Drought in 2006 has seen the lowest ever recorded rainfall in towns such as Lockhart , Tarcutta and Narrandera . 
