Hi,
I don’t know much and I am certain there are members very educated on the correct temperature for budgies but I do know avoid any cage positions that may in the path of a cool draft. I currently have my home temperature on 30 degrees Celsius throughout the night and 28 degrees Celsius through the day. I have a heat pad on his play table that is set at 24-26 degrees Celsius. If these temperatures are to hot throughout the day I turn it down. Weather in Australian winter/autumn/spring are very unpredictable; it’s either very hot or very cold. When it’s warm we take him outside to sit in the sun for a couple of minutes then sit in the shade. Hope this helps somewhat. Good luck!