Hong Kong Observatory vs RainViewer
Same instrument, two spec sheets — measured, not claimed.
Hong Kong Observatory vs RainViewer: common questions
Which is more reliable, Hong Kong Observatory or RainViewer?
Both are neck-and-neck — Hong Kong Observatory and RainViewer each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.
Which is faster, Hong Kong Observatory or RainViewer?
RainViewer has the lower median latency in our checks — Hong Kong Observatory responds in 1415 ms versus RainViewer at 551 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 Hong Kong Observatory and RainViewer need an API key?
Neither needs a paid key — Hong Kong Observatory 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 Hong Kong Observatory and RainViewer from the browser?
Yes — both Hong Kong Observatory 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 Hong Kong Observatory and RainViewer free for commercial use?
Hong Kong Observatory 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.