To be a 'freak' you need to add columns for wind speed and direction, sunrise and sunset [solar heat gain], cloudy or not. The draft in the chimney, and temperature in the chimney recorded on a drum-recorder... Need to weigh the ash to compare with weight of coal added in previous 24hrs.
Now all the above would be a bit much.. but oops I forgot,, a Bacharach exhaust gass tester to record CO and CO2 levels so burn effiecency can be calculated..
I just keep the hopper full, and look at the amount of ash at the end of the week..