Weather Postin’ retrieves the current weather provided from RSS Weather when your post is published. After that, when you view your posts the weather conditions will display at the end of your post. This does not alter the original text of the post; it is only displayed at run-time.
Please note, that posts prior to activation will not have weather associated with them. Yes, obvious, but worth saying. :o)
Te puedes descargar este plugin para utilizarlo en tu instalación autoalojada de WordPress.