I think I would bring them in front the cold.depending on how cold it gets.not sure .but me I would bring them in if the temperature was going to get under 55 degrees at night.I'm sure someone will be able to give you a better idea on when to bring them in.lol I would worry my birds would get cold and sick outside.blessings and keep us posted.
princess Gracie Barber welcomes you all and blessings
It would be helpful to have additional information regarding your current situation with your aviary.
How many budgies do you have?
Do you have a large flight cage (or can you purchase one) in which you could house them indoors during the winter months?
Is the aviary enclosed or are the sides open to the elements?
I would personally not want my budgies to be exposed to temperatures below 12-13 C.
While the birds may be able to withstand the temperatures, drafts are not good for them and if they have a weakened immune system they are more likely to become ill.
Although in the outback of Australia they may have to deal with temperatures ranging from 10 - 46 C I believe by
choosing to have budgies in a domestic situation we owe it to our budgies to provide better conditions than they would have were they born "in the wild".
Cloud's avian vet told me the temperature should not be lower than 72-70 F. Even 65 F is kinda low temp. for budgies as far as I know. I will be better safe than sorry and try to find a way to keep the lil ones indoors.
Usually, when photos are uploaded as attachments, they for some reason default to landscape format, so it's usually less of a hassle to insert pictures from Photobucket as the photos are larger and easier to orient
My budgies are outside all year and I live in Scandinavia. -10 C is not uncommon during winter. The largest part of the aviary is in an old, unheated building - it doesn't keep them out of the cold, but it keeps them out of snow, rain, wind and drafts.
As long as the birds are acclimatized, having lived outside since summer, the cold doesn't harm them. But it does make any underlying condition more likely to show its ugly face, and as such diseases are more common during winter. But if we are talking healthy birds that are properly acclimatized, and an aviary that keeps them dry and out of wind and drafts, 6 C shouldn't be a problem at all.