New Zealand. New Zealand is fairly temperate year-round, so you can plan your vacation any time of year and expect generally the same weather. Northern New Zealand is a sub-tropical region, while Southern New Zealand is arid and brisk. Nowhere in New Zealand does the average high temperature reach above about 25 degrees Celsius.
"How enzymes -- the biological proteins that act as catalysts and help complex reactions occur -- are 'tuned' to work at a particular temperature is described in new research from groups in New Zealand and the UK including the University of Bristol."