I said it was the NWS API. Not hiding anything.
I am working with 'Forecast' data. In the referenced Marto's reply post, they are trying to work with 'Latest Observations' which has even more issues than the Forecast data. I am sticking with the Latest Observations XML data from the NWS that comes from a different source than the NWS API. It has been much more reliable. Unfortunately they don't do the forecast data in XML like the latest observations, or I would use it instead right now.
The NWS API is newer but it has been out for a few years now. It should be much more stable than it is at this point.