Facts
Like any other animals on this planet, parrots are extremely sensitive and intelligent. They are 'by nature' wild, reason why they are meant to be able to fly away from danger.
A warning for 'people' who claim to be able to train a wild bird: it takes years and sometimes it simply will not work, in the process of wanting to tame a bird the parrot might start mutilating itself and worst simply die from stress.
Some birds 'might' be ok outside, in the cold and rain, however this is not advisable a parrot is meant to be warm and the cold might simply kill it, many people bring their birds back in the warm during winter, or simply add a 'safe heater'.
They 'all say' a parrot is better in an aviary, I personally dispute this case, if your bird is very tamed and used in living with people it is very unlikely it will enjoy living outside, the reverse is equally true.
Bare in mind that keeping a parrot is very expensive with the daily vegs and fruits, add-on vitamins and seeds mixes, toys and cage. There is also the 'vet' bills and the fact that if your bird is tamed your favorite pass time will be reduced in keeping company to your bird.
The true is that parrots are birds and to care for them you must have a very calm, forgiving and patient type person.