The difference between weather and whether
TLDR: Weather involves rain, not alternatives.
I see these two mixed up all the time, even in the published media, which is a shame.
weather (noun)—the condition of the atmosphere in regards to heat, wetness, cloudiness etc.
The weather changed from bad to worse as the day progressed.
‘This is perfect weather for a picnic!’ Clarence exclaimed.
Darwin experienced a number of unexpected weather patterns over the space of a week.
weather (verb)—the process of something being worn away by atmospheric conditions; and to withstand a difficulty
The sea captain’s face was weathered by twenty long years at sea.
The ship weathered the stormy crossing quite well.
There are also a few sayings you may have heard of, including:
Josh was feeling a little under the weather.
Meaning: Josh was feeling a bit sick.
‘You don’t need to make such heavy weather about it, John!’
Meaning: John doesn’t need to make the task more difficult than it needs to be.
‘Matthew, keep a weather eye on that dial and tell me when it moves.’
Meaning: Matthew should watch the dial very carefully for any sign of change.
whether (conjunction)—used to express a choice between two or more alternatives; or expressing a doubt
Sarah wasn’t sure whether she liked the new house or not.
Tom decided he would walk down to the beach to see whether the tide was high or low.
For information on the usage of whether and if, click here.