They are most comfortable between 18 and 22 degrees. Anything below 15 is too cold, so keeping them outside year round takes a lot of work in winter for warmth but also summer can become too hot. Anything above 25 risks heat stroke.
It’s best, if you have the option, to keep them indoors full time during winter. If not, be prepared for with plenty of insulating measures, moving into sheds, and hours heating up heatpads!
And in summer, bringing them in when there are heatwaves and temperatures above 25.
Getting indoor piggies used to being able to stay out at night during summer just takes a few weeks preparation. You treat them like tender plants. Out in the day but in at night for a few weeks, once the risk of frost has passed and they are acclimated to outside, they can stay out at night as well.
Mine live in my shed year round. So for me, them being outside at night now does not require any measures as they are well used to it.
I can keep them warm enough in the shed in winter (lots of measures needed) although still have a plan to bring them in if there is a bad winter. Summer is where I struggle as outside can become too hot in hutches and sheds so they come in the house during heatwaves and at the peak of summer.
