Do you remember going out on Christmas morning into the freshly fallen snow? Wearing matching hat, scarf, and gloves? Making snowmen and angels, having snowball fights, and sledding? Seems familiar right?
Actually, white Christmases are very rare. So rare (and so heavily bet upon) that the Met Office had to change its definition of a white Christmas to ‘at least one snowflake observed falling in the 24 hours of 25th December in the UK’. That definition doesn’t exactly fill us with the Christmas spirit
Plane accidents are rare too. But it’s easy to think of plane crashes and white Christmases (because TV, films etc.) so we overestimate how likely they are to happen. When things seem familiar to us, we overestimate how likely they are. That’s called availability bias.
Interestingly, the most snow days actually happen in February, but I’m dreaming of a White Valentine’s doesn’t have the same ring.