What moisture content should my outdoor soil be at?

I'm growing outdoor in raised beds. I amended my raised bedding mix with build-a-soil potting mix, coco loco, epsom salts, bone meal, and supercharge mycorrhizae/bacteria booster. My ph/hygrometer is showing around 52% moisture level right now. Plants are looking great, but there's going to be a few hot days coming up. What's the optimal level of soil moisture to have?