Home-assistant has a loot of good sensor platforms that consumes the state from other sensors, it would be grate to get a easy wizard to setup those sensors or create “virtual sensors” as a blueprint based on templates in the UI.
Some samples for the existing utility sensors:
trend sensor to find out if temp is falling or rising
Statistics to get the mean and a loot of attributs
min_max to also get several nice statistics
Derivative that estimates the derivative of the values provided by a source sensor
There is also several other powerfull sensors like Riemann sum integral and Bayesian sensor to estimate the probability.