Here's why and some alternatives:
* No direct translation: Bonfire night is a specifically British celebration, and there isn't a single equivalent event in France.
* Closest alternatives:
* La nuit de la Saint-Jean: This is the closest French equivalent, celebrated on June 23rd with bonfires, music, and dancing. It's more about celebrating the summer solstice.
* Fête du Feu: This translates to "Fire Festival" and could be used to describe a general celebration involving bonfires.
Ultimately, the best way to explain Bonfire Night to a French speaker is to describe the specific event:
* "La nuit où les Britanniques brûlent des feux de joie pour célébrer la fin de la saison d'automne." (The night when the British burn bonfires to celebrate the end of autumn.)
You could also simply say "Bonfire Night" and explain what it is.