When I started using the NWS API regularly about 2 months ago, the Current Obs were consistently coming back 4 or more hours old. The Current Obs are only supposed to be around an hour old at most.

The forecasts at the time were coming back 2-4 hour old, but the NWS says that is about correct for those, as they are not updated as often. I just got back data for one location that is 239 hours old (loads the same old date in web browser matching the server version). Another forecast location has been giving back 503 error since late last night (both browser and server).

For the Current Obs, instead of using (Station KMCO as example)

https://api.weather.gov/stations/KMCO/observations/latest

you would use

https://w1.weather.gov/xml/current_obs/KMCO.xml

to get the data. If you do this from a browser, you will get a style sheet version, just use view source to see the pure XML.

There are some differences, but most of the basic information is the same. The XML data has been much more stable than the API versions.

Hope that helps.