Daily data are compiled by Weather Station every 10 minutes for each station. These data are kept for the current day only (local time).
The historical data are compiled by Weather Station once a day for each station after being subjected to a number of computations, such as daily minimum and maximum, etc. All of this data can be stored indefinitely depending on your settings.
Average value, maximum value, mid-range value, minimum value.
Amplitude, average value, maximum value, median value, mid-range value, minimum value, standard deviation.