PM2.5 Open Data Portal vs Weatherstack

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

Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms796309
P95 · ms13521372
AuthnoneapiKey
CORSnono
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — no API keyFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

PM2.5 Open Data Portal vs Weatherstack: common questions

Which is more reliable, PM2.5 Open Data Portal or Weatherstack?

Both are neck-and-neck — PM2.5 Open Data Portal and Weatherstack 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, PM2.5 Open Data Portal or Weatherstack?

Weatherstack has the lower median latency in our checks — PM2.5 Open Data Portal responds in 796 ms versus Weatherstack at 309 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 PM2.5 Open Data Portal and Weatherstack need an API key?

PM2.5 Open Data Portal needs no key, while Weatherstack requires a free API key. If you want to start calling without signup, reach for PM2.5 Open Data Portal first.

Can I call PM2.5 Open Data Portal and Weatherstack from the browser?

Neither sends browser-friendly CORS headers reliably, so call PM2.5 Open Data Portal and Weatherstack from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.

Are PM2.5 Open Data Portal and Weatherstack free for commercial use?

PM2.5 Open Data Portal has unclear commercial terms, and Weatherstack 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.