@Ray
Hi, I do not know your set up nor do I know when the “in one day” changes to the next day at OpenWeaterMap.
I use the API Key exactly in this module and only have one instance of the mirror running…
I just checked my statistics at OpenWeaterMap and I do have at about 112 calls a day. Which is correct as my mirror is shutdown between 11:30pm and 5am.
Maybe it is a matter of your timezone and calls of the last day are counted in the current one.
What does your statistic look like
https://home.openweathermap.org/statistics/onecall_30
Edit:
And one small side note. Even if you use different keys the calls a summarized per account