Composting toilets can be used in all climates. The composting process will stop during very cold weather. If possible, keep the composting chamber a heated part of the home and/or insulate it.

Outdoor composting also works. A hot compost bin can be used even in the coldest climates. A cold climate composter writes on Joe Jenkins’s forum,

“This is our second winter of composting our humanure, and it has been a great success.
We’ve had a very cold winter so far. It has been consistently below zero for most of the last 3 weeks. It was -24 yesterday morning, but it was a sunny day so it warmed up to -12 and we decided we’d better take advantage of this “warm spell” to go empty the buckets.
When we checked the thermometer in the active bin, it was 112F. We’re so happy that our compost buddies (that’s what I call our microbe friends) are able to keep things toasty in spite of our very wintery weather.”
D and C
Alaska, January 2012