Theoretically no, the database we used contains weather station data from all over the world. However during our analysis we found that the quality of data from

Theoretically no, the database we used contains weather station data from all over the world. However during our analysis we found that the quality of data from international stations was a lot more varied - as measured by many factors such as geographical distribution of stations, regularity of measurements and number of implausible outliers. I would still like to come back to this eventually & try to iron out as many of those issues as possible - but for the scope of this project it was much easier to just use US data as it is extremely well-curated.