Meaning of "Rio de Janeiro": January River — A Navigator's Mistake

Rio de Janeiro = Portuguese for "River of January."

Origin Story

• January 1, 1502: Portuguese expedition (Gonçalo Coelho, Amerigo Vespucci) enters Guanabara Bay.
• Mistake: They thought the bay was the mouth of a great river.
• Naming: "Rio de Janeiro" — River of [the month of] January.

Reality

• Guanabara Bay is an oceanic bay — not a river mouth.
• No major river enters there. The city grew on the western shore.
• Actual rivers: Rio de Janeiro (small, canalized), Rio São João, Rio Meriti — minor.

Name Persistence

Bay → City (1565, São Sebastião do Rio de Janeiro) → State (1763) → Capital (1763–1960). The error became identity.

Cultural Echo

Cariocas (residents) joke: "We're the only city named after a mistake that stuck." The name evokes summer, arrival, discovery — fitting for a city of spectacle.