Unless someone is feeding a particular airport's ATIS recording, you will not be able to find it anywhere online. The ATIS recording is recorded by the controllers for that particular airport. It is updated hourly with the latest weather. About 80 to 90 percent of the ATIS is the weather, with the rest containing airport specific information such as active runway, local NOTAMs, etc. There's a ton of things that can go into an ATIS and by definition, the weather is a small part. As for a regular ATIS, it's mainly the weather (which is the METAR you read).
An ATIS can change under several situations, with the most often occurrence being a change in weather or airport conditions.
Although, if someone out there knows where to find current ATIS recordings online, that would be sweet! But I am nor aware of any site out there that has this information, again, because of their localized nature and tendency to change frequently.