Weather means the state of the atmosphere — rain, sun, wind: "The weather turned cold overnight." Whether introduces a choice or a doubt and can usually be swapped for "if": "I can't decide whether to go." If the sentence is not about the sky, you almost certainly want whether.
These sound the same in most accents, which is why the error slips past proofreading. The meanings could hardly be further apart: weather is a noun about the atmosphere, whether is a conjunction that sets up alternatives.
How to use weather
As a noun: "The weather forecast says heavy rain." "We had glorious weather all week."
Weather is also a verb, meaning to come through something difficult, or to wear away through exposure:
- "The firm weathered the recession better than its rivals."
- "The stone has weathered to a soft grey."
And note the idiom "under the weather", meaning slightly unwell.
How to use whether
Whether introduces an indirect question or a pair of options:
- "She asked whether the deadline had moved."
- "I don't know whether he's coming."
- "Whether you agree or not, the decision stands."
- "We'll finish on time whether or not the parts arrive."
The test
Try substituting if. If the sentence still works, you want whether: "I don't know if he's coming" is fine, so whether is the spelling. Try substituting rain or the forecast instead — if that is the sense, you want weather.
The one place if will not substitute is before or not and before to: "whether or not", "whether to go". That is a signal in itself — if the next words are or not or an infinitive, the spelling is whether.
Whether vs if, honestly
Traditional advice says to reserve if for conditions and whether for alternatives. In practice, careful writers use if for indirect questions all the time, and no one misreads "Let me know if you're free." The distinction is worth observing only where genuine ambiguity arises:
"Tell me if the shipment is delayed" could mean tell me only in the event of a delay. "Tell me whether the shipment is delayed" clearly asks for an answer either way. When the difference matters, use whether.
Finally, a word occasionally confused with both: wether, a castrated ram. It is a real farming term, which is why a spellchecker may not flag it.
Frequently Asked Questions
Is it "whether or not" or "weather or not"?
"Whether or not." It sets up two possibilities. Weather only ever refers to atmospheric conditions or to enduring something difficult.
Can I use "if" instead of "whether"?
Usually yes in everyday writing. Prefer whether when the sentence could be misread as a condition, and always before "or not" or an infinitive: "whether to accept".
What does "weather the storm" mean?
It uses the verb weather, meaning to come through a difficult period without being destroyed: "The business weathered the storm and reopened in spring."