Just clarified this in the README:

* Input value ranges are as follows:

- Station name: non null UTF-8 string of min length 1 character and max length 100 characters

- Temperature value: non null double between -99.9 (inclusive) and 99.9 (inclusive), always with one fractional digit

* Implementations must not rely on specifics of a given data set, e.g. any valid station name as per the constraints above and any data distribution (number of measurements per station) must be supported