Bright Sky (DWD) vs RainViewer

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified (attribution requested)
Free tierUnlimited, no key, no credit cardFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Bright Sky (DWD) vs RainViewer: common questions

Which is more reliable, Bright Sky (DWD) or RainViewer?

On our scheduled checks, RainViewer leads on measured uptime — Bright Sky (DWD) at —% versus RainViewer 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 Bright Sky (DWD) and RainViewer need an API key?

Neither needs a paid key — Bright Sky (DWD) is callable with no signup, and RainViewer is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call Bright Sky (DWD) and RainViewer from the browser?

Yes — both Bright Sky (DWD) and RainViewer 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 Bright Sky (DWD) and RainViewer free for commercial use?

Bright Sky (DWD) has unclear commercial terms, and RainViewer 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.