The South Australian outback is in the grip of a scorching heatwave, record-breaking in some parts with temperatures consistently reaching the mid-40s. Oodnadatta, 900 kilometres north of Adelaide, is on target for its longest stretch of 45-degree heat on record. After hitting 45 for the fourth day in a row on Thursday, the far north town is almost certain to break its record on Friday and possibly beat its record on Saturday. In more than 60 years of records Oodnadatta's previous longest stretch of 45-degree days was five, in 2004. Other records have already been broken this week in the outback. On Tuesday, Woomera had its hottest day in more than 60 years of records, hitting 48.1 degrees, 14 above average. Also on Tuesday, state's highest temperature in 21 years was recorded, 48.5 degrees at Roxby Downs. The SA record is 50.7 degrees, in January 1960 at Oodnadatta. The mid-40s heat will continue north and west of about Coober Pedy for a few more days before it gets nudged back into the WA interior. Adelaide will get a taste of it this weekend and early next week, when 40 degrees is a chance ahead of a weak cooler change. The heat will be back in Adelaide on Thursday.