The ac network weather blog has created a Google Earth layer to display current METAR weather conditions from NOAA for many regions throughout the Earth. Just find the location of interest and click on the dot. The pop-up balloon contains a link to a website with additional information about the station/airport.
METAR weather reports are typically generated every hour and are generally used by pilots. A typical METAR report contains data for the temperature, dew point, wind speed and direction, precipitation, cloud cover and heights, visibility, and barometric pressure. METAR data is presented in a format that takes a bit of experience to understand. The Weather Underground has put together a great tutorial for decoding METAR data.