SmogRank / World / Japan / Saitama / December 2025

Most polluted cities in Saitama, Japan, December 2025

31 cities in Saitama, Japan ranked by their average PM2.5 over the 31 days. Worst: Misato, Saitama at 12.6 µg/m³, #903 of 2,960 cities in the world. Cleanest: Ogawamachi at 6.0. A city needs measurements on 70% of the days to be ranked.

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.

← Sōka 3% 3%0

Every city in Saitama, Japan ranked for December 2025, 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.

1Sōka
3%
2Misato, Saitama
3%
3Koshigaya
3%
4Kazo
3%
5Gyōda
0%
6Hanyū
0%
7Kasukabe
0%
8Saitama
0%
9Asaka
0%
10Kōnosu
0%
10Igusa
0%
12Kukichūō
0%
12Kawaguchi
0%
14Ageo
0%
15Niiza
0%
16Tokorozawa
0%
17Sakado
0%
17Higashi-Matsuyama
0%
19Kumagaya
0%
20Kawagoe
0%
21Hannō
0%
21Iruma
0%
23Morohongō
0%
24Menuma
0%
25Sayama
0%
26Kodamachō-kodamaminami
0%
27Chichibu
0%
28Yorii
0%
29Honjō
0%
30Minano
0%
31Ogawamachi
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

All cities in the world, December 2025 · All cities in Japan, December 2025 · Saitama now

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SmogRank, most polluted cities in Saitama, Japan, PM2.5, December 2025, smogrank.com/jp/region/saitama/history/2025-12 (accessed 7 Oct 2026).

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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.