SmogRank / World / Asia / Japan / Niigata

Most polluted cities in Niigata, Japan

12 measured cities, this year; 12 above the WHO annual guideline. Worst: Itoigawa at 9.8 µg/m³, #1,039 in the world.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

Gunma: 9 measured citiesIbaraki: 19 measured citiesIshikawa: 9 measured citiesNagano: 11 measured citiesNiigata: 12 measured citiesTochigi: 11 measured citiesToyama: 8 measured citiesYamagata: 8 measured citiesFukushima: 7 measured citiesGifu: 15 measured cities#12 Niitsu-honchō: 6.8 µg/m³#11 Maki: 6.9 µg/m³#9 Shirone: 7.5 µg/m³#10 Minamiuonuma: 7.5 µg/m³#8 Niigata: 7.7 µg/m³#7 Kameda-honchō: 7.8 µg/m³#5 Nagaoka: 7.9 µg/m³#6 Sado: 7.9 µg/m³#4 Seirō: 8.8 µg/m³#3 Jōetsu: 9.6 µg/m³#2 Shibata: 9.7 µg/m³#1 Itoigawa: 9.8 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Seirō 0% 0.75%0
Every measured city in Niigata, Japan, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Seirōlast full day 2 Oct 0%
  2. 2Itoigawa 0%
  3. 3Shibata 0%
  4. 4Jōetsulast full day 30 Sept 0%
  5. 5Nagaoka 0%
  6. 5Sado 0%
  7. 7Kameda-honchō 0%
  8. 8Niigata 0%
  9. 9Shirone 0%
  10. 9Minamiuonuma 0%
  11. 11Maki 0%
  12. 12Niitsu-honchō 0%
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Niigata cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Sanjō≈ 6 µg/m³Good
Kashiwazaki≈ 7 µg/m³Good
Tsubame≈ 6 µg/m³Good
Murakami≈ 4 µg/m³Good
Tōkamachi≈ 6 µg/m³Good
Gosen≈ 5 µg/m³Good
Mitsuke≈ 6 µg/m³Good
Agano≈ 6 µg/m³Good
Ojiya≈ 6 µg/m³Good
Uonuma≈ 5 µg/m³Good
Myoko≈ 7 µg/m³Good
Muikamachi≈ 6 µg/m³Good
Tainai≈ 5 µg/m³Good
Arai≈ 7 µg/m³Good
Kamo≈ 5 µg/m³Good
Yoshida-kasugachō≈ 6 µg/m³Good
Tochio-honchō≈ 6 µg/m³Good
Suibara≈ 6 µg/m³Good
Shiozawa≈ 6 µg/m³Good
Muramatsu≈ 5 µg/m³Good
Ryōtsu-minato≈ 5 µg/m³Good

Bad-air episodes in Niigata

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

Use this board

SmogRank, most polluted cities in Niigata, Japan, PM2.5, this year to 6 Oct 2026, 22:00 UTC, smogrank.com/jp/region/niigata?w=year.

Download top 10 (PNG)

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.