API to get current weather conditions for any point on Earth

Question

I'm in the planning phase of a project and one of the requirements is that the system be able to get the current weather conditions for any point on Earth, given a set of latitude-longitude coordinates.

I signed up for Wunderground.com's Weather API, but immediately realized this wouldn't work. If you enter a set of coordinates that doesn't correspond to a known city, the API returns a "querynotfound" error with the description "No cities match your search query."

Does a service like this exist?

EDIT: To clarify, I might need the current weather conditions for some arbitary point in (say) the Atlantic ocean.

Answer 1

Have you looked at google api?

http://www.google.com/ig/api?weather=,,,40467626,-03609910&hl=es

I think this is what you are looking for Using Google Weather API with Lat and Lon - how to format?

Edited 29th Aug 2012

As mentioned by "azgolfer" as of August 25th, 2012. Google has phased out it's API. Try http://www.wunderground.com/ instead.