Type 'easy' or 'hard' to begin the quiz. Easy is a 15-degree grid, hard is a 10-degree grid. Then, try to name the LARGEST city in each grid square which fits the category label for each square. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the largest city accepted in that square (100 being you named the largest city).
LETTER: means the city starts with that letter.
NUMBER RANGE: (such as 2-5, 10+) means the city contains that many letters (excluding spaces and special characters).
POPULATION RANGE: (such as 50-100K) means the city has that range for its population.
2+ WORDS means the city name has 2 or more words (words denoted by a space or hyphen).
At the end of the quiz the largest population missed answer will show in each unanswered square, and for those answered the largest city will be listed if you didn't answer it.
Quiz Takers 
The European Commission needs to update their numbers or something… I mean, only one of the Nordic urban areas are listed, neither is Edmonton or Ottawa…
surely Helsinki should be listed on there… as well as many Russian cities (Ufa, Samara, Omsk etc.)
populations were slightly under 1M for those urban centres per the source.
well you should use another source then as they are all over 1M (Helsinki city proper is under but urban area is over)
this is the source that had the temperature data however so I’m stuck using it for these urban centre quizzes. urban areas are defined different ways from source to source too