Any St. Louis pool owners having a lot of evaporation? Or do I have a leak?

Our 18 x 36 inground vinyl pool seems to be losing water for the first time this year. I would say about 1/8-1/4 inch per day. Could be evaporation, as the St. Louis area has had a lot of rain all summer and it hasn't rained lately (where I live). What are any other pool owners in the St. Louis Metro region experiencing? Is this an expected amount? I'm getting ready to do the bucket test tonight but I am so worried!

I'm not in St Louis, but have similar weather, being in the middle of MO.

I've not noted a huge difference in evaporation, but I've been keeping my pool covered about 12 hours a day to conserve heat with the unusual cooler weather we've been having.

Bucket test would be a good idea.