Butter stays hard below 15 C (depending on variable like fat content). Fridge is 4 C. 8 months of the year my kitchen is below 15 C. I do not live in the tropi

Butter stays hard below 15 C (depending on variable like fat content). Fridge is 4 C. 8 months of the year my kitchen is below 15 C. I do not live in the tropics or even the subtropics.