The only exception to that rule I would say is it might be useful to have your own lightning strike sensor if your nearest airport doesn't have one. Lightning strike data is highly local and time sensitive. You can learn a lot about which clouds a small airplane should fly through 'right now' and which ones you should not, just looking at lightning strikes.
Otherwise, your tax dollars are paying for those airport readings, use the data you're footing the bill for already, imo ;).
Otherwise, your tax dollars are paying for those airport readings, use the data you're footing the bill for already, imo ;).