Is The Weather Channel accurate?
Weather.com and its app, owned by IBM, one of the most-visited weather services in the US.
The Weather Channel runs a closed, proprietary blend, so its exact accuracy cannot be independently verified. It is built on the same open models we grade — which we score directly. Watching those models is the honest way to judge it.
How The Weather Channel makes its forecast. The Weather Channel uses IBM's proprietary forecast (the GRAF system) layered on the same public models everyone else starts from. The blend is closed and cannot be graded independently. That matters, because it means the accuracy you get from The Weather Channel is really the accuracy of the models underneath it — the same models we test, in the open, against the recorded weather.
Our verdict. A polished product built on public model data plus a closed blend. Since no one can verify the closed part, comparing the open models directly — as we do — is the honest way to judge accuracy.
Which forecast is most accurate in the US?
CheckWeather Score — graded against the weather that actually happened
The CheckWeather Score blends temperature, wind and rain accuracy — each measured against ERA5 (the recorded weather) over the last 30 days across 300 cities. Lower error means a higher score. The apps you know (AccuWeather, Apple Weather, The Weather Channel) are built on these models.