Sorry, going back to the snow. It’s because it was the victorians who really started the whole ‘Christmas holiday’ thing, including introducing Christmas trees, cards etc. During the 19th century we had a mini ‘ice age’ and England had much harsher winters (people used to skate on the Thames). With the likes of Dickens et al, these harsher winters became embedded in Christmas lore

Movies have a more limited time period to get the plot through to the audience

Why did my postman leave a paper parcel on my doorstep in the pouring rain?