There are some notable differences between Cortana in the United States and other countries. While some of them are major, such as general availability and features included, others are minor. A small tweak that makes a Cortana a lot more useful to international users is that temperature results can now displayed in Celsius without having to ask for the result to specifically be Celsius.
Though the change is probably welcomed to many, it still seems to be deciding which unit system you prefer. Even though my Weather app is set to Fahrenheit, my weather updates via Cortana are in Celsius . That being said, the demographic for wanting to see Fahrenheit in foreign countries rather than Celsius is probably rather small so overall it seems to be a positive change.
In case you ever are stuck in a foreign land and don’t have Cortana or a unit converter handy, I have picked up a rather easy trick. To get close, just remember that 10° Celsius is 50° Fahrenheit and that for every 5° C you go in either direction it’s about 10° F of difference. It’s a rough estimate but if you’re without the internet and somehow see the temperature in the wrong units it could be your only hope of knowing what to wear.