Station catalog from Iowa Environmental Mesonet’s ASOS network metadata, fetched per-state via their GeoJSON API and pre-bundled into stations.json by tools/build-stations-json.py. The file refreshes on demand; ASOS stations don’t move and the official list churns at maybe one station per month nationwide, so weekly is more than enough.
Click any marker for the station’s ICAO, name, county, WFO, elevation, and a deep link to its hourly observations page. Current conditions (temperature, wind, pressure, sky) lazy-load from api.weather.gov on click — a single fetch per station, no per-page-load polling. Stations that haven’t reported in a while will say so honestly rather than show stale data.
Tony’s 13 watched stations from the Forecasts page render as gold diamonds for quick visual reference. Everything else is a small grey dot; clustering at low zoom keeps the CONUS view readable, and clusters unspiderfy as you zoom in.