Hacker News Reader

Is this used as data and visualisation for windy.com?

I always thought it was their proprietary software. Nice!

I suspect both of these (and other weather / meterological visualisers) draw on the same data sources.

Nullschool lists its sources on the "about" page. Weather data generally come from GFS (Global Forecast System): EMC / NCEP / NWS / NOAA.