Much of Australia’s southeast is set to endure at least two warm nights in a row as a heatwave sets in. Severe conditions have hit South Australia – including Adelaide – and regional Victoria on Sunday, with some regions copping temperatures above 40C. The rest of Victoria, Tasmania and western and southern parts of NSW will likely see the hottest temperatures on January 25, while the mercury will climb the highest on Tuesday for eastern NSW and Greater Sydney. In NSW on Sunday afternoon, temperatures had already risen to 37C in Sydney’s west and 41C at Hay in the state’s western Riverina region. Bureau of Meteorology senior meteorologist Gabrielle Woodhouse said heat records were unlikely to tumble over the coming days and people across SA, Victoria and NSW were unlikely to sleep easy. “The important part with the heat we’re seeing is those overnight temperatures remaining particularly warm,” Woodhouse told …