IPMA vs US Weather

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearyes
Data licenseIPMA open data (attribution 'Fonte: IPMA' expected)U.S. Government work / public domain
Free tierFree, no keyFree (US Government public data)
Rate limitUnpublishedUnpublished (asks for a User-Agent identifying your app)
In directory since2026-07-052026-07-05
operationalpartialdownno data

IPMA vs US Weather: common questions

Which is more reliable, IPMA or US Weather?

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

Do IPMA and US Weather need an API key?

Neither needs a paid key — IPMA 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 IPMA and US Weather from the browser?

Yes — both IPMA and US Weather send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.

Are IPMA and US Weather free for commercial use?

IPMA 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.