DFlight API vs US Weather

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

Uptime · 30d
Uptime · 90d11.8%100%
Uptime · 30d0.0%100%
P50 · ms319223
P95 · ms6682086
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearyes
Data licenseUnverifiedU.S. Government work / public domain
Free tierFree — limits not publishedFree (US Government public data)
Rate limitUnpublishedUnpublished (asks for a User-Agent identifying your app)
In directory since2026-07-052026-07-05
operationalpartialdownno data

DFlight API vs US Weather: common questions

Which is more reliable, DFlight API or US Weather?

On our scheduled checks, US Weather leads on measured uptime — DFlight API at 11.8% versus US Weather 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, DFlight API or US Weather?

US Weather has the lower median latency in our checks — DFlight API responds in 319 ms versus US Weather at 223 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 DFlight API and US Weather need an API key?

Neither needs a paid key — DFlight API is callable with no signup, and US Weather is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call DFlight API and US Weather from the browser?

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

Are DFlight API and US Weather free for commercial use?

DFlight API has unclear commercial terms, and US Weather allows commercial use on its free tier. 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.