AviationWeather vs Weather Underground API

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d93.1%100%
Uptime · 30d91.7%100%
P50 · ms450104
P95 · ms47341117
AuthnoneapiKey
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useyesunclear
Data licensePublic domain (U.S. Government / NOAA)Unverified
Free tierFree, no keyFree tier — API key may be required for production
Rate limitUnpublished (NWS requests reasonable use)Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

AviationWeather vs Weather Underground API: common questions

Which is more reliable, AviationWeather or Weather Underground API?

On our scheduled checks, Weather Underground API leads on measured uptime — AviationWeather at 93.1% versus Weather Underground API at 100% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Which is faster, AviationWeather or Weather Underground API?

Weather Underground API has the lower median latency in our checks — AviationWeather responds in 450 ms versus Weather Underground API at 104 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.

Do AviationWeather and Weather Underground API need an API key?

AviationWeather needs no key, while Weather Underground API requires a free API key. If you want to start calling without signup, reach for AviationWeather first.

Can I call AviationWeather and Weather Underground API from the browser?

Only Weather Underground API is browser-friendly — it returns CORS headers over HTTPS. AviationWeather needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are AviationWeather and Weather Underground API free for commercial use?

AviationWeather allows commercial use on its free tier, and Weather Underground API has unclear commercial terms. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.