Castalia (pronounced "Cas-tale-yuh"), is a town in Nash County, North Carolina, United States.

[4] According to the United States Census Bureau, the town has a total area of 0.7 square miles (1.8 km2), all land.

Castalia, being located in eastern North Carolina, has long hot humid summers, and winters which are short and mild by comparison to much of the rest of the country, with snow being a rarity.

In Castalia, between 60 and 90 days per year are over 86 degrees Fahrenheit, according to the Heat Zone Map published by the American Horticultural Society.

[6] These hot days, combined with the South's high humidity, make it sweltering in the summer.