Netro app keeps changing the amount of rainfall that we have had. Day before yesterday it rained heavily. The very next day Netro app showed that it rained 1 inch. Today it’s showing that on that same day it rained only 0.33 inch. Any idea why it keeps fluctuating for something that has already happened in the past?

How does Netro app calculate subsoil moisture levels? Note that I don’t have any sensors. Please advise