They can make an informed guess based on what they see and feel and smell. Someone told me the other day they can smell ozone in the air when there’s rain coming. Not sure how good your nose is but do this for a month and children learn a lot about our weather. Given the forecasters rarely get it right the children stand a good chance of being pretty close.
It matters in every day life as we make decisions about hanging out washing, taking a jacket, shoes or jandals, outside job or curl up with a book? I think its good practise to help our children learn to be self reliant and make good decisions as well as understanding seasons and weather.
Take care and keep warm!