Parts of southeast Queensland had their warmest September day in more than 70 years today and it will get even hotter later in the week. While a sea breeze kept Brisbane from reaching 30 degrees on Monday afternoon, temperatures soared into the high thirties further west. Amberley Airport's top of 38.2 degrees today was 13 above average for this time of year and the highest September temperature recorded at the site since 1943. The mercury managed to reach 32.6 degrees at Maroochydore, making it their warmest September day since 2003. Today's hot weather was a prelude to what is forecast to be record-breaking September heat across southern Queensland later this week. The mercury is forecast to reach 39 degrees at Amberley on Thursday, which is close to the site's September record of 39.2C from 1943. Brisbane's forecast top of 37 degrees on Thursday may challenge the city's September record of 38.3 degrees from 1943. Before this unseasonable heat targets southeast Queensland on Thursday, the state's southwest is likely to see September records tumble for the second time in a week. Thargomindah's new September heat record of 40.4 degrees from Saturday is expected be outdone by a 42 degree maximum on Wednesday. Birdsville is forecast to reach a searing 43 degrees on Wednesday, which would trump their old September record of 42.4 degrees from 2003. This would also be the highest temperature ever recorded in Queensland during September and may also challenge the national record. The highest temperature ever recorded in Australia during September was 43.1 degrees at West Roebuck in Western Australia during 2003.