How were they being kept at their previous home? While I would have no hesitation putting birds that age and amount of feathering outside ( Frankly I put my day old chicks outside in the coop, with a heat source), What is appropriate for you and your birds may differ. If for example these chicks are accustomed to being kept at temperatures well above what your outdoor temperature is currently are it may be necessary to gradually accustom them to the temperatures outside. If these chicks have been being kept outside then they are already accustomed to those temperatures.