AVG value calculating

Im using EMONCMS 8.5. One of many values monitored by my system is current outdoor temperature. Im logging temperature each 60 seconds and calculating MAX, MIN a delta daily value. In older version of EMONCMS I have calculated also average daily value of temperature with dailytimestore graph in VIS. But now in 8.5 is dailytimestore no more available. Feed for logging temperature by me is phpfiwa, so averaging should be available somehow. Which way to calculate and presenting avarage daily temperature is the right one?

Radek