IPMA vs RainViewer
Same instrument, two spec sheets — measured, not claimed.
IPMA vs RainViewer: common questions
Which is more reliable, IPMA or RainViewer?
On our scheduled checks, RainViewer leads on measured uptime — IPMA at 98.0% versus RainViewer 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, IPMA or RainViewer?
RainViewer has the lower median latency in our checks — IPMA responds in 1024 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 IPMA and RainViewer need an API key?
Neither needs a paid key — IPMA 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 IPMA and RainViewer from the browser?
Yes — both IPMA 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 IPMA and RainViewer free for commercial use?
IPMA 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.