OVH Weathermarp question

A new server I set up today is in BHS 6. Looking at the weathermap it seems there aren't too many racks on that location

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Is there any explanation of how should I read this map? Is it a room? What does it mean? I like the colors a lot except the grey but that's not enough

 

BHS 5 looks much better

 

If you don't understand this map there is no way I'll understand it so