Let's assume a planet like ours, same size and same conditions. My characters live at approximately 60° North, in a boreal forest, with a climate much like the Nordic countries in Europe. They are travelling south and need to encounter a hot desert much like Sahara. This desert has to be placed as close to the boreal area as possible and still be believable as a hot desert. I've done some research and the Gobi desert, which is placed at ~45°N, is too extreme with temperatures as low as -40°C during winter nights and as hot as +50°C during summer days. This could be a good starting point, though, if it's possible to have a desert approximately this far north but make it less cold during winter nights (let's say no colder than -5°C).
Any factors that is true on earth, like warm or cold air and water currents, could play a part in bringing these biomes closer together.
I am looking for:
- The shortest possible distance between a boreal area with cold winters and a hot desert that should not be colder than approx. -5°C during winter nights.
- The factors that make it possible to place these very different biomes so close together.
(I am new and I hope this belongs here and not on the Earth Science site.)