National Grid ESO vs Weatherstack

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

Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms609309
P95 · ms13111372
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseNESO Open Data Licence (OGL-based); varies per datasetUnverified
Free tierFree — limits not publishedFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

National Grid ESO vs Weatherstack: common questions

Which is more reliable, National Grid ESO or Weatherstack?

Both are neck-and-neck — National Grid ESO 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, National Grid ESO or Weatherstack?

Weatherstack has the lower median latency in our checks — National Grid ESO responds in 609 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 National Grid ESO and Weatherstack need an API key?

National Grid ESO needs no key, while Weatherstack requires a free API key. If you want to start calling without signup, reach for National Grid ESO first.

Can I call National Grid ESO and Weatherstack from the browser?

Only National Grid ESO is browser-friendly — it returns CORS headers over HTTPS. Weatherstack needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are National Grid ESO and Weatherstack free for commercial use?

National Grid ESO 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.