The current metro area population of Nagano in 2026 is 363,000, a 0.27% decline from 2025.

• The metro area population of Nagano in 2025 was 364,000, a 0.55% decline from 2024.
• The metro area population of Nagano in 2024 was 366,000, a 0.27% decline from 2023.
• The metro area population of Nagano in 2023 was 367,000, a 0.54% decline from 2022.