Recommended way to find daily averages

[null0007]

Looking at the temporal aspect of the data returned by the layers in the gridpoint datasets, what is the best way to calculate daily average temperature or humidity? Calling the API to return numerical data for a gridpoint only shows the absolute latest data. If I make a call in the middle of the day, then the temperature values start in the middle of the day along with the future forecast.

At least for average temperature, I thought about using the min/max temp values. The same problem applies. For example, the first max temp is only available for the rest of the day such as "2021-02-02T13:00:00+00:00/PT13H".