No, the word 'whether' is a conjunction that precedes a choice of two options or an inquiry. Examples:I don't know whether she knows it or not.I'll ask her whether she does.The homonym weather is a noun, a common noun, a general word for conditions of the atmosphere at a given place and time; a word for any weather anywhere.The word 'weather' is also a verb: weather, weathers, weathering, weathered.Another homonym, wether is a noun, a common noun, a general word for a castrated male sheep; a word for any such sheep anywhere.