SmogRank / Episodes / Japan
Japan, May 2025
For 2 days, from 20 to 21 May 2025, 103 cities in Japan had PM2.5 at least twice their usual for the time of year. The worst reading was Ayase, Kanagawa, Japan: 33.7 µg/m³ on 20 May, about 3.5× its usual 9.6.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 103 in 1 country
Days 2 20 to 21 May 2025
Worst day 21 May 77 cities counted
Furthest above usual 3.9× Saku
Day by day
Play 21 May 77 cities at twice their usual or more
Nonoichi Kanazawa Tsubata Oyabe Ibi Tsuruga Gero Sekimachi Takaoka Mizuho Hakui Kakamigahara Minokamo Himimachi Inuyama Ichinomiya Kani Kaizu Hikone Nanao Ama Tajimi Seto Obama Nisshin Anamizu Ōmihachiman Tōkai Yokkaichi Kitahama Toyota Kariya Chiryū Kōka Suzuka Anjō Tokoname Kusatsu Handa Hekinan Okazaki Ōtsu Nishio Kaminoma Ina Kyoto Okaya Gamagōri Iga Ueno-ebisumachi Uji Kōtari Jōyō Minamichita Kameoka Shinshiro Yawata Matsusaka Toyohashi Kizugawa Sugai Nabari Saikū Tahara Takatsuki Hirakata Kyōtango Yono Ise Nagano Toba Ueda Ikoma Kosai Tenri Hōryūji Toyonaka Higashiosaka Hamakita Suzaka Osaka Kashihara-shi Yao Shima Takarazuka Hamamatsu Tanba Amagasaki Habikino Nishinomiya Iwata Tondabayashichō Fukuroi Sakai Sayama Minami-Alps Kakegawa Kawachi-Nagano Nishiwaki Kobe Izumi Shimada Hashimoto Kishiwada Kikugawa Fujieda Owase Shizuoka Izumisano Akashi Kinokawa Fujinomiya Sennan Iwade Kumano Fuji Fujiyoshida Himeji Ikaruga Minato Kainan Minamiuonuma Sumoto Shingū Gotemba Numazu Susono Aioi Arida Sado Izunokuni Nagaoka Kariya Minamiashigara Sakai-nakajima Gobō Atami Tanabe Odawara Bizen Shimoda Ōta Narutochō-mitsuishi Kumagaya Maki Tsuyama Sayama Ashikaga Hiratsuka Tokorozawa Higashimurayama Kawagoe Tokushima Shirone Machida Kodaira Fuchū Hanyū Higashikurume Anan Fujisawa Kazo Noborito Niitsu-honchō Niigata Shido Kameda-honchō Okayama Kamojimachō-jōgejima Kamakura Saitama Kukichūō Hiragi Tamano Yoshinogawa Koga Takamatsu Tokyo Kawaguchi Tochigi Kasukabe Kanuma Miura Yokosuka Sōja Koshigaya Oyama Sōka Kurashiki Kurihama Bandō Takahashi Takinomiya Noda Shibata Misato, Saitama Utsunomiya Matsudo Kaminokawa Niimi Yonago Urayasu Jōsō Kimitsu Marugame Shimo-tsuma Chikusei Kashiwa Asakuchi Zentsujichó Sakaiminato Kisarazu Kamagaya Yasugichō Mooka Tateyama Narashino Toride Kasaoka Sodegaura Minamibōsō Ichihara Yachiyo Chiba Nasushiobara Kan’onjichō Naka Inzai Matsue Aizu-Wakamatsu Fukuyama Ajiki Ishioka Kasama Shin’ichi Inashiki Narita Yachimata Mobara Ōami Unnan Tōgane Hitachiomiya Katsuura Mito Ōhara Izumo Nankoku Sawara Yokoshiba Mihara Hokota Yonezawa Hitachi-Naka Nagai Miyoshi Sōsa Kōriyama Kochi Omigawa Kashima-shi Kamisu Hitachi Ino Tsuruoka Imabari Fukushima Ōdachō-ōda Kitaibaraki Higashihiroshima Choshi Yamagata Yae Shinagawa Iwaki Shiroishi Higashine Kure Gion Matsuyama Hiroshima Gōtsuchō Kakuda Iyo Minami-Sōma Sōma Hamada Iwanuma Natori-shi Sendai Ōtake Iwakuni Yoshioka Tagajō-shi Masuda Yanai Matsushima Ōsaki Higashimatsushima Hikari Wakuya Kudamatsu Shūnan Ishinomaki Tome Hōfu Kunisaki Shikokuchūō Onomichi Owariasahi Niihama Gyōda Kurayoshi Jōetsu Nyūzen Toki Uozu Kashiwara Imizu Sagae Saijō Asaka Igusa Itoigawa Takehara Tatebayashi Nantan Takashima Kofu Toyooka Mima Ikedachō Kakogawachō-honmachi Kameyama Iruma Higashi-Matsuyama Niiza Tsuchiura Minawa Gifu Honjō Kodamachō-kodamaminami Kōnosu Menuma Numata Sakado Shibukawa Yorii Miyazu Ōtsuki Sandachō Kuwana Hashima Ageo Fukui-shi Nagoya Yokota Inabe Minamirinkan Tsu Aihara Kiryū Komatsu Matsutō Morohongō Nakanojō Sano Tomioka Tottori-shi Toyama Tatsuno Higashinozoe Youkaichi Tonami Chichibu Hannō Mikuni Fukuchiyama Ono Kaga Hachiōji Ogawamachi Ōme Yaita Ayabe Maizuru Nagahama Atsugi Shirakawa Chikuma Iida Matsumoto Ōgaki Takayama Ayase Yamato Azamino Hadano Akishima Imaichi Yokohama Chigasaki Ono Sabae Ebina Sakura Nasukarasuyama Saku Suwa Yamanashi 17 May 18 19 20 21 22 23 24 Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.
How it spread
Kurayoshi Kurayoshi, 17 May: 7.3 µg/m³, 0.7× usual Kurayoshi, 18 May: 14.0 µg/m³, 1.4× usual Kurayoshi, 19 May: 31.4 µg/m³, 3.1× usual Kurayoshi, 20 May: 23.7 µg/m³, 2.3× usual Kurayoshi, 21 May: 26.6 µg/m³, 2.6× usual Kurayoshi, 22 May: 8.6 µg/m³, 0.8× usual Kurayoshi, 23 May: 11.1 µg/m³, 1.1× usual Kurayoshi, 24 May: 9.8 µg/m³, 1.0× usual Ayase Ayase, 17 May: 9.1 µg/m³, 0.9× usual Ayase, 18 May: 13.3 µg/m³, 1.4× usual Ayase, 19 May: 20.0 µg/m³, 2.1× usual Ayase, 20 May: 33.7 µg/m³, 3.5× usual Ayase, 21 May: 25.1 µg/m³, 2.6× usual Ayase, 22 May: 8.1 µg/m³, 0.8× usual Ayase, 23 May: 11.1 µg/m³, 1.2× usual Ayase, 24 May: 11.0 µg/m³, 1.1× usual Ōtsuki Ōtsuki, 17 May: 13.9 µg/m³, 1.3× usual Ōtsuki, 18 May: 16.3 µg/m³, 1.5× usual Ōtsuki, 19 May: 18.6 µg/m³, 1.7× usual Ōtsuki, 20 May: 25.8 µg/m³, 2.4× usual Ōtsuki, 21 May: 32.9 µg/m³, 3.0× usual Ōtsuki, 22 May: 17.3 µg/m³, 1.6× usual Ōtsuki, 23 May: 16.0 µg/m³, 1.5× usual Ōtsuki, 24 May: 17.2 µg/m³, 1.6× usual Yamanashi Yamanashi, 17 May: 9.0 µg/m³, 1.1× usual Yamanashi, 18 May: 13.3 µg/m³, 1.6× usual Yamanashi, 19 May: 16.4 µg/m³, 2.0× usual Yamanashi, 20 May: 28.5 µg/m³, 3.5× usual Yamanashi, 21 May: 31.8 µg/m³, 3.9× usual Yamanashi, 22 May: 16.7 µg/m³, 2.1× usual Yamanashi, 23 May: no reading Yamanashi, 24 May: 12.8 µg/m³, 1.6× usual Ikedachō Ikedachō, 17 May: 9.5 µg/m³, 0.9× usual Ikedachō, 18 May: 14.1 µg/m³, 1.4× usual Ikedachō, 19 May: 20.3 µg/m³, 2.0× usual Ikedachō, 20 May: 29.4 µg/m³, 2.9× usual Ikedachō, 21 May: 25.6 µg/m³, 2.5× usual Ikedachō, 22 May: 8.1 µg/m³, 0.8× usual Ikedachō, 23 May: 14.6 µg/m³, 1.4× usual Ikedachō, 24 May: 12.8 µg/m³, 1.2× usual Ayabe Ayabe, 17 May: 7.2 µg/m³, 0.8× usual Ayabe, 18 May: 14.4 µg/m³, 1.7× usual Ayabe, 19 May: 16.8 µg/m³, 2.0× usual Ayabe, 20 May: 29.1 µg/m³, 3.4× usual Ayabe, 21 May: 17.4 µg/m³, 2.0× usual Ayabe, 22 May: 5.7 µg/m³, 0.7× usual Ayabe, 23 May: 11.4 µg/m³, 1.3× usual Ayabe, 24 May: 7.6 µg/m³, 0.9× usual Chigasaki Chigasaki, 17 May: 9.1 µg/m³, 1.2× usual Chigasaki, 18 May: 14.5 µg/m³, 1.9× usual Chigasaki, 19 May: 17.8 µg/m³, 2.3× usual Chigasaki, 20 May: 29.0 µg/m³, 3.7× usual Chigasaki, 21 May: 21.9 µg/m³, 2.8× usual Chigasaki, 22 May: 5.9 µg/m³, 0.8× usual Chigasaki, 23 May: 10.0 µg/m³, 1.3× usual Chigasaki, 24 May: 11.6 µg/m³, 1.5× usual Fukuchiyama Fukuchiyama, 17 May: 7.2 µg/m³, 0.8× usual Fukuchiyama, 18 May: 12.3 µg/m³, 1.4× usual Fukuchiyama, 19 May: 15.1 µg/m³, 1.8× usual Fukuchiyama, 20 May: 28.7 µg/m³, 3.3× usual Fukuchiyama, 21 May: 17.0 µg/m³, 2.0× usual Fukuchiyama, 22 May: 4.2 µg/m³, 0.5× usual Fukuchiyama, 23 May: 9.6 µg/m³, 1.1× usual Fukuchiyama, 24 May: 8.9 µg/m³, 1.0× usual Kofu Kofu, 17 May: 9.2 µg/m³, 0.9× usual Kofu, 18 May: 12.1 µg/m³, 1.2× usual Kofu, 19 May: 14.9 µg/m³, 1.5× usual Kofu, 20 May: 25.8 µg/m³, 2.6× usual Kofu, 21 May: 28.6 µg/m³, 2.8× usual Kofu, 22 May: 12.3 µg/m³, 1.2× usual Kofu, 23 May: 5.6 µg/m³, 0.6× usual Kofu, 24 May: 11.0 µg/m³, 1.1× usual Mima Mima, 17 May: 7.3 µg/m³, 0.8× usual Mima, 18 May: 16.6 µg/m³, 1.7× usual Mima, 19 May: 22.6 µg/m³, 2.4× usual Mima, 20 May: 27.4 µg/m³, 2.9× usual Mima, 21 May: 28.2 µg/m³, 2.9× usual Mima, 22 May: 7.4 µg/m³, 0.8× usual Mima, 23 May: 16.2 µg/m³, 1.7× usual Mima, 24 May: 14.3 µg/m³, 1.5× usual Nagahama Nagahama, 17 May: 6.1 µg/m³, 0.7× usual Nagahama, 18 May: 14.0 µg/m³, 1.7× usual Nagahama, 19 May: 17.9 µg/m³, 2.2× usual Nagahama, 20 May: 28.0 µg/m³, 3.4× usual Nagahama, 21 May: 21.9 µg/m³, 2.6× usual Nagahama, 22 May: 5.8 µg/m³, 0.7× usual Nagahama, 23 May: 12.0 µg/m³, 1.4× usual Nagahama, 24 May: 10.5 µg/m³, 1.3× usual Ebina Ebina, 17 May: 7.4 µg/m³, 1.0× usual Ebina, 18 May: 11.5 µg/m³, 1.6× usual Ebina, 19 May: 16.6 µg/m³, 2.3× usual Ebina, 20 May: 27.3 µg/m³, 3.8× usual Ebina, 21 May: 21.3 µg/m³, 3.0× usual Ebina, 22 May: 5.4 µg/m³, 0.8× usual Ebina, 23 May: 11.6 µg/m³, 1.6× usual Ebina, 24 May: 11.4 µg/m³, 1.6× usual Maizuru Maizuru, 17 May: 8.2 µg/m³, 1.0× usual Maizuru, 18 May: 13.8 µg/m³, 1.7× usual Maizuru, 19 May: 13.4 µg/m³, 1.7× usual Maizuru, 20 May: 26.7 µg/m³, 3.4× usual Maizuru, 21 May: 17.7 µg/m³, 2.2× usual Maizuru, 22 May: 10.4 µg/m³, 1.3× usual Maizuru, 23 May: 10.7 µg/m³, 1.4× usual Maizuru, 24 May: 10.5 µg/m³, 1.3× usual Ono Ono, 17 May: 8.7 µg/m³, 1.1× usual Ono, 18 May: 12.9 µg/m³, 1.6× usual Ono, 19 May: 16.4 µg/m³, 2.0× usual Ono, 20 May: 26.7 µg/m³, 3.3× usual Ono, 21 May: 13.8 µg/m³, 1.7× usual Ono, 22 May: 5.5 µg/m³, 0.7× usual Ono, 23 May: 14.2 µg/m³, 1.8× usual Ono, 24 May: 9.8 µg/m³, 1.2× usual Higashinozoe Higashinozoe, 17 May: 8.8 µg/m³, 1.1× usual Higashinozoe, 18 May: 14.1 µg/m³, 1.7× usual Higashinozoe, 19 May: 15.9 µg/m³, 1.9× usual Higashinozoe, 20 May: 26.5 µg/m³, 3.2× usual Higashinozoe, 21 May: 7.1 µg/m³, 0.9× usual Higashinozoe, 22 May: 5.3 µg/m³, 0.6× usual Higashinozoe, 23 May: 13.1 µg/m³, 1.6× usual Higashinozoe, 24 May: 8.3 µg/m³, 1.0× usual Nantan Nantan, 17 May: 7.6 µg/m³, 0.8× usual Nantan, 18 May: 13.5 µg/m³, 1.4× usual Nantan, 19 May: 15.2 µg/m³, 1.6× usual Nantan, 20 May: 26.5 µg/m³, 2.8× usual Nantan, 21 May: 16.1 µg/m³, 1.7× usual Nantan, 22 May: 6.9 µg/m³, 0.7× usual Nantan, 23 May: 13.7 µg/m³, 1.5× usual Nantan, 24 May: 9.8 µg/m³, 1.0× usual Minamirinkan Minamirinkan, 17 May: 8.0 µg/m³, 1.0× usual Minamirinkan, 18 May: 12.5 µg/m³, 1.5× usual Minamirinkan, 19 May: 17.5 µg/m³, 2.1× usual Minamirinkan, 20 May: 26.4 µg/m³, 3.1× usual Minamirinkan, 21 May: 23.9 µg/m³, 2.8× usual Minamirinkan, 22 May: 7.6 µg/m³, 0.9× usual Minamirinkan, 23 May: 10.2 µg/m³, 1.2× usual Minamirinkan, 24 May: 12.0 µg/m³, 1.4× usual Yokohama Yokohama, 17 May: 7.1 µg/m³, 1.0× usual Yokohama, 18 May: 11.5 µg/m³, 1.6× usual Yokohama, 19 May: 16.0 µg/m³, 2.2× usual Yokohama, 20 May: 26.3 µg/m³, 3.6× usual Yokohama, 21 May: 18.6 µg/m³, 2.5× usual Yokohama, 22 May: 6.8 µg/m³, 0.9× usual Yokohama, 23 May: 10.1 µg/m³, 1.4× usual Yokohama, 24 May: 10.0 µg/m³, 1.4× usual Sandachō Sandachō, 17 May: 7.3 µg/m³, 0.8× usual Sandachō, 18 May: 12.6 µg/m³, 1.4× usual Sandachō, 19 May: 15.7 µg/m³, 1.8× usual Sandachō, 20 May: 26.2 µg/m³, 3.0× usual Sandachō, 21 May: 9.4 µg/m³, 1.1× usual Sandachō, 22 May: 5.6 µg/m³, 0.6× usual Sandachō, 23 May: 14.7 µg/m³, 1.7× usual Sandachō, 24 May: 9.3 µg/m³, 1.1× usual Miyazu Miyazu, 17 May: 7.6 µg/m³, 0.9× usual Miyazu, 18 May: 12.3 µg/m³, 1.4× usual Miyazu, 19 May: 15.2 µg/m³, 1.8× usual Miyazu, 20 May: 26.1 µg/m³, 3.0× usual Miyazu, 21 May: 20.2 µg/m³, 2.3× usual Miyazu, 22 May: 5.2 µg/m³, 0.6× usual Miyazu, 23 May: 9.1 µg/m³, 1.1× usual Miyazu, 24 May: 7.6 µg/m³, 0.9× usual Kameyama Kameyama, 17 May: 6.7 µg/m³, 0.8× usual Kameyama, 18 May: 14.0 µg/m³, 1.6× usual Kameyama, 19 May: 19.0 µg/m³, 2.1× usual Kameyama, 20 May: 26.1 µg/m³, 2.9× usual Kameyama, 21 May: 23.5 µg/m³, 2.6× usual Kameyama, 22 May: 4.5 µg/m³, 0.5× usual Kameyama, 23 May: 12.0 µg/m³, 1.3× usual Kameyama, 24 May: 12.5 µg/m³, 1.4× usual Tatsuno Tatsuno, 17 May: 7.7 µg/m³, 1.0× usual Tatsuno, 18 May: 10.4 µg/m³, 1.3× usual Tatsuno, 19 May: 14.3 µg/m³, 1.8× usual Tatsuno, 20 May: 26.0 µg/m³, 3.2× usual Tatsuno, 21 May: 14.2 µg/m³, 1.8× usual Tatsuno, 22 May: 5.4 µg/m³, 0.7× usual Tatsuno, 23 May: 12.7 µg/m³, 1.6× usual Tatsuno, 24 May: 8.2 µg/m³, 1.0× usual Saijō Saijō, 17 May: 15.4 µg/m³, 1.3× usual Saijō, 18 May: 12.4 µg/m³, 1.0× usual Saijō, 19 May: 20.9 µg/m³, 1.8× usual Saijō, 20 May: 24.5 µg/m³, 2.1× usual Saijō, 21 May: 33.2 µg/m³, 2.8× usual Saijō, 22 May: 10.9 µg/m³, 0.9× usual Saijō, 23 May: 12.4 µg/m³, 1.0× usual Saijō, 24 May: 13.4 µg/m³, 1.1× usual Tottori-shi Tottori-shi, 17 May: 9.0 µg/m³, 0.9× usual Tottori-shi, 18 May: 14.4 µg/m³, 1.5× usual Tottori-shi, 19 May: 16.1 µg/m³, 1.7× usual Tottori-shi, 20 May: 23.5 µg/m³, 2.4× usual Tottori-shi, 21 May: 30.8 µg/m³, 3.2× usual Tottori-shi, 22 May: 10.6 µg/m³, 1.1× usual Tottori-shi, 23 May: 10.8 µg/m³, 1.1× usual Tottori-shi, 24 May: 9.8 µg/m³, 1.0× usual Tomioka Tomioka, 17 May: 10.6 µg/m³, 1.1× usual Tomioka, 18 May: 10.3 µg/m³, 1.1× usual Tomioka, 19 May: 14.1 µg/m³, 1.5× usual Tomioka, 20 May: 16.0 µg/m³, 1.7× usual Tomioka, 21 May: 30.7 µg/m³, 3.2× usual Tomioka, 22 May: 27.5 µg/m³, 2.9× usual Tomioka, 23 May: 16.0 µg/m³, 1.7× usual Tomioka, 24 May: 11.0 µg/m³, 1.1× usual Sabae Sabae, 17 May: 5.0 µg/m³, 0.6× usual Sabae, 18 May: 11.7 µg/m³, 1.5× usual Sabae, 19 May: 11.7 µg/m³, 1.5× usual Sabae, 20 May: 22.0 µg/m³, 2.8× usual Sabae, 21 May: 29.9 µg/m³, 3.8× usual Sabae, 22 May: 14.0 µg/m³, 1.8× usual Sabae, 23 May: 11.3 µg/m³, 1.4× usual Sabae, 24 May: 11.6 µg/m³, 1.5× usual Kiryū Kiryū, 17 May: 8.4 µg/m³, 0.9× usual Kiryū, 18 May: 9.1 µg/m³, 1.0× usual Kiryū, 19 May: 13.3 µg/m³, 1.4× usual Kiryū, 20 May: 15.9 µg/m³, 1.7× usual Kiryū, 21 May: 29.5 µg/m³, 3.2× usual Kiryū, 22 May: 18.2 µg/m³, 2.0× usual Kiryū, 23 May: 10.1 µg/m³, 1.1× usual Kiryū, 24 May: 10.8 µg/m³, 1.2× usual Shibukawa Shibukawa, 17 May: 9.3 µg/m³, 0.9× usual Shibukawa, 18 May: 9.3 µg/m³, 0.9× usual Shibukawa, 19 May: 12.2 µg/m³, 1.2× usual Shibukawa, 20 May: 17.5 µg/m³, 1.8× usual Shibukawa, 21 May: 29.5 µg/m³, 3.0× usual Shibukawa, 22 May: 24.3 µg/m³, 2.5× usual Shibukawa, 23 May: 12.6 µg/m³, 1.3× usual Shibukawa, 24 May: 12.5 µg/m³, 1.3× usual Kodamachō-kodamamin… Kodamachō-kodamaminami, 17 May: 9.7 µg/m³, 1.0× usual Kodamachō-kodamaminami, 18 May: 11.1 µg/m³, 1.1× usual Kodamachō-kodamaminami, 19 May: 13.0 µg/m³, 1.3× usual Kodamachō-kodamaminami, 20 May: 17.4 µg/m³, 1.7× usual Kodamachō-kodamaminami, 21 May: 29.5 µg/m³, 3.0× usual Kodamachō-kodamaminami, 22 May: 22.5 µg/m³, 2.3× usual Kodamachō-kodamaminami, 23 May: 10.4 µg/m³, 1.0× usual Kodamachō-kodamaminami, 24 May: 12.5 µg/m³, 1.3× usual Niihama Niihama, 17 May: 14.0 µg/m³, 1.2× usual Niihama, 18 May: 12.5 µg/m³, 1.1× usual Niihama, 19 May: 19.6 µg/m³, 1.6× usual Niihama, 20 May: 22.4 µg/m³, 1.9× usual Niihama, 21 May: 29.3 µg/m³, 2.5× usual Niihama, 22 May: 9.9 µg/m³, 0.8× usual Niihama, 23 May: 10.9 µg/m³, 0.9× usual Niihama, 24 May: 15.8 µg/m³, 1.3× usual Mikuni Mikuni, 17 May: 6.9 µg/m³, 0.8× usual Mikuni, 18 May: 11.6 µg/m³, 1.3× usual Mikuni, 19 May: 15.0 µg/m³, 1.7× usual Mikuni, 20 May: 19.9 µg/m³, 2.3× usual Mikuni, 21 May: 28.7 µg/m³, 3.3× usual Mikuni, 22 May: 15.3 µg/m³, 1.8× usual Mikuni, 23 May: 9.2 µg/m³, 1.1× usual Mikuni, 24 May: 11.2 µg/m³, 1.3× usual Jōetsu Jōetsu, 17 May: 11.8 µg/m³, 1.1× usual Jōetsu, 18 May: 15.3 µg/m³, 1.4× usual Jōetsu, 19 May: 13.8 µg/m³, 1.3× usual Jōetsu, 20 May: 18.9 µg/m³, 1.8× usual Jōetsu, 21 May: 28.5 µg/m³, 2.7× usual Jōetsu, 22 May: 14.6 µg/m³, 1.4× usual Jōetsu, 23 May: 9.8 µg/m³, 0.9× usual Jōetsu, 24 May: 11.5 µg/m³, 1.1× usual Chichibu Chichibu, 17 May: 11.1 µg/m³, 1.3× usual Chichibu, 18 May: 9.7 µg/m³, 1.1× usual Chichibu, 19 May: 10.6 µg/m³, 1.2× usual Chichibu, 20 May: 16.7 µg/m³, 1.9× usual Chichibu, 21 May: 28.4 µg/m³, 3.3× usual Chichibu, 22 May: 21.1 µg/m³, 2.4× usual Chichibu, 23 May: 8.4 µg/m³, 1.0× usual Chichibu, 24 May: 11.3 µg/m³, 1.3× usual Morohongō Morohongō, 17 May: 9.1 µg/m³, 1.0× usual Morohongō, 18 May: 11.5 µg/m³, 1.3× usual Morohongō, 19 May: 13.2 µg/m³, 1.5× usual Morohongō, 20 May: 18.8 µg/m³, 2.1× usual Morohongō, 21 May: 28.1 µg/m³, 3.2× usual Morohongō, 22 May: 17.9 µg/m³, 2.0× usual Morohongō, 23 May: 9.6 µg/m³, 1.1× usual Morohongō, 24 May: 11.9 µg/m³, 1.3× usual Kaga Kaga, 17 May: 7.1 µg/m³, 0.9× usual Kaga, 18 May: 11.3 µg/m³, 1.4× usual Kaga, 19 May: 14.3 µg/m³, 1.8× usual Kaga, 20 May: 21.3 µg/m³, 2.6× usual Kaga, 21 May: 27.9 µg/m³, 3.4× usual Kaga, 22 May: 14.2 µg/m³, 1.8× usual Kaga, 23 May: 9.0 µg/m³, 1.1× usual Kaga, 24 May: 12.2 µg/m³, 1.5× usual Yorii Yorii, 17 May: 9.1 µg/m³, 1.0× usual Yorii, 18 May: 9.6 µg/m³, 1.0× usual Yorii, 19 May: 12.1 µg/m³, 1.3× usual Yorii, 20 May: 16.9 µg/m³, 1.8× usual Yorii, 21 May: 27.9 µg/m³, 3.0× usual Yorii, 22 May: 18.2 µg/m³, 1.9× usual Yorii, 23 May: 9.7 µg/m³, 1.0× usual Yorii, 24 May: 11.9 µg/m³, 1.3× usual Ōme Ōme, 17 May: 8.8 µg/m³, 1.1× usual Ōme, 18 May: 11.0 µg/m³, 1.4× usual Ōme, 19 May: 13.6 µg/m³, 1.7× usual Ōme, 20 May: 20.4 µg/m³, 2.5× usual Ōme, 21 May: 27.6 µg/m³, 3.4× usual Ōme, 22 May: 17.0 µg/m³, 2.1× usual Ōme, 23 May: 8.6 µg/m³, 1.1× usual Ōme, 24 May: 10.0 µg/m³, 1.2× usual Hannō Hannō, 17 May: 8.6 µg/m³, 1.0× usual Hannō, 18 May: 10.5 µg/m³, 1.3× usual Hannō, 19 May: 14.6 µg/m³, 1.7× usual Hannō, 20 May: 19.9 µg/m³, 2.4× usual Hannō, 21 May: 27.6 µg/m³, 3.3× usual Hannō, 22 May: 16.0 µg/m³, 1.9× usual Hannō, 23 May: 9.4 µg/m³, 1.1× usual Hannō, 24 May: 12.3 µg/m³, 1.5× usual Menuma Menuma, 17 May: 8.1 µg/m³, 0.9× usual Menuma, 18 May: 9.4 µg/m³, 1.0× usual Menuma, 19 May: 13.8 µg/m³, 1.5× usual Menuma, 20 May: 18.5 µg/m³, 2.0× usual Menuma, 21 May: 27.6 µg/m³, 3.0× usual Menuma, 22 May: 14.4 µg/m³, 1.5× usual Menuma, 23 May: 9.9 µg/m³, 1.1× usual Menuma, 24 May: 11.5 µg/m³, 1.2× usual Sano Sano, 17 May: 6.9 µg/m³, 0.8× usual Sano, 18 May: 8.2 µg/m³, 1.0× usual Sano, 19 May: 11.1 µg/m³, 1.3× usual Sano, 20 May: 18.7 µg/m³, 2.2× usual Sano, 21 May: 27.5 µg/m³, 3.2× usual Sano, 22 May: 14.1 µg/m³, 1.7× usual Sano, 23 May: 9.5 µg/m³, 1.1× usual Sano, 24 May: 10.4 µg/m³, 1.2× usual Nakanojō Nakanojō, 17 May: 9.1 µg/m³, 1.1× usual Nakanojō, 18 May: 7.2 µg/m³, 0.8× usual Nakanojō, 19 May: 8.0 µg/m³, 0.9× usual Nakanojō, 20 May: 16.7 µg/m³, 1.9× usual Nakanojō, 21 May: 27.5 µg/m³, 3.2× usual Nakanojō, 22 May: 22.4 µg/m³, 2.6× usual Nakanojō, 23 May: 11.5 µg/m³, 1.3× usual Nakanojō, 24 May: 9.7 µg/m³, 1.1× usual Shikokuchūō Shikokuchūō, 17 May: 9.4 µg/m³, 0.8× usual Shikokuchūō, 18 May: 13.0 µg/m³, 1.1× usual Shikokuchūō, 19 May: 20.7 µg/m³, 1.8× usual Shikokuchūō, 20 May: 24.3 µg/m³, 2.1× usual Shikokuchūō, 21 May: 27.5 µg/m³, 2.4× usual Shikokuchūō, 22 May: 8.5 µg/m³, 0.7× usual Shikokuchūō, 23 May: 12.1 µg/m³, 1.0× usual Shikokuchūō, 24 May: 11.4 µg/m³, 1.0× usual Toyama Toyama, 17 May: 9.2 µg/m³, 1.1× usual Toyama, 18 May: 13.0 µg/m³, 1.5× usual Toyama, 19 May: 12.0 µg/m³, 1.4× usual Toyama, 20 May: 19.5 µg/m³, 2.3× usual Toyama, 21 May: 27.4 µg/m³, 3.2× usual Toyama, 22 May: 15.4 µg/m³, 1.8× usual Toyama, 23 May: 10.3 µg/m³, 1.2× usual Toyama, 24 May: 10.4 µg/m³, 1.2× usual Ageo Ageo, 17 May: 8.1 µg/m³, 0.9× usual Ageo, 18 May: 11.6 µg/m³, 1.3× usual Ageo, 19 May: 15.6 µg/m³, 1.8× usual Ageo, 20 May: 21.7 µg/m³, 2.5× usual Ageo, 21 May: 27.3 µg/m³, 3.1× usual Ageo, 22 May: 12.6 µg/m³, 1.4× usual Ageo, 23 May: 11.2 µg/m³, 1.3× usual Ageo, 24 May: 12.5 µg/m³, 1.4× usual Iruma Iruma, 17 May: 9.1 µg/m³, 1.0× usual Iruma, 18 May: 11.5 µg/m³, 1.3× usual Iruma, 19 May: 15.3 µg/m³, 1.7× usual Iruma, 20 May: 19.6 µg/m³, 2.2× usual Iruma, 21 May: 27.3 µg/m³, 3.0× usual Iruma, 22 May: 16.8 µg/m³, 1.8× usual Iruma, 23 May: 9.8 µg/m³, 1.1× usual Iruma, 24 May: 12.1 µg/m³, 1.3× usual Ono Ono, 17 May: 4.3 µg/m³, 0.6× usual Ono, 18 May: 10.6 µg/m³, 1.5× usual Ono, 19 May: 12.1 µg/m³, 1.7× usual Ono, 20 May: 19.3 µg/m³, 2.7× usual Ono, 21 May: 27.1 µg/m³, 3.8× usual Ono, 22 May: 7.4 µg/m³, 1.0× usual Ono, 23 May: 10.0 µg/m³, 1.4× usual Ono, 24 May: 9.8 µg/m³, 1.4× usual Imaichi Imaichi, 17 May: 7.1 µg/m³, 0.9× usual Imaichi, 18 May: 5.8 µg/m³, 0.8× usual Imaichi, 19 May: 8.6 µg/m³, 1.1× usual Imaichi, 20 May: 13.7 µg/m³, 1.8× usual Imaichi, 21 May: 27.1 µg/m³, 3.6× usual Imaichi, 22 May: 18.9 µg/m³, 2.5× usual Imaichi, 23 May: 8.4 µg/m³, 1.1× usual Imaichi, 24 May: 7.7 µg/m³, 1.0× usual Uozu Uozu, 17 May: 13.8 µg/m³, 1.4× usual Uozu, 18 May: 15.8 µg/m³, 1.6× usual Uozu, 19 May: 15.6 µg/m³, 1.6× usual Uozu, 20 May: 23.7 µg/m³, 2.4× usual Uozu, 21 May: 27.1 µg/m³, 2.7× usual Uozu, 22 May: 15.9 µg/m³, 1.6× usual Uozu, 23 May: 11.9 µg/m³, 1.2× usual Uozu, 24 May: 12.7 µg/m³, 1.3× usual Gyōda Gyōda, 17 May: 8.4 µg/m³, 0.8× usual Gyōda, 18 May: 11.3 µg/m³, 1.1× usual Gyōda, 19 May: 16.1 µg/m³, 1.6× usual Gyōda, 20 May: 21.0 µg/m³, 2.0× usual Gyōda, 21 May: 27.1 µg/m³, 2.6× usual Gyōda, 22 May: 14.6 µg/m³, 1.4× usual Gyōda, 23 May: 11.5 µg/m³, 1.1× usual Gyōda, 24 May: 13.1 µg/m³, 1.3× usual Suwa Suwa, 17 May: 6.2 µg/m³, 0.9× usual Suwa, 18 May: 10.4 µg/m³, 1.5× usual Suwa, 19 May: 12.2 µg/m³, 1.7× usual Suwa, 20 May: 20.9 µg/m³, 3.0× usual Suwa, 21 May: 27.0 µg/m³, 3.9× usual Suwa, 22 May: 9.2 µg/m³, 1.3× usual Suwa, 23 May: 13.9 µg/m³, 2.0× usual Suwa, 24 May: 11.0 µg/m³, 1.6× usual Tonami Tonami, 17 May: 10.4 µg/m³, 1.3× usual Tonami, 18 May: 11.3 µg/m³, 1.4× usual Tonami, 19 May: 11.8 µg/m³, 1.5× usual Tonami, 20 May: 18.7 µg/m³, 2.3× usual Tonami, 21 May: 27.0 µg/m³, 3.3× usual Tonami, 22 May: 15.0 µg/m³, 1.9× usual Tonami, 23 May: 8.9 µg/m³, 1.1× usual Tonami, 24 May: 9.8 µg/m³, 1.2× usual Shirakawa Shirakawa, 17 May: 5.9 µg/m³, 0.8× usual Shirakawa, 18 May: 5.6 µg/m³, 0.7× usual Shirakawa, 19 May: 11.8 µg/m³, 1.6× usual Shirakawa, 20 May: 16.5 µg/m³, 2.2× usual Shirakawa, 21 May: 26.9 µg/m³, 3.5× usual Shirakawa, 22 May: 9.8 µg/m³, 1.3× usual Shirakawa, 23 May: 7.3 µg/m³, 1.0× usual Shirakawa, 24 May: 9.1 µg/m³, 1.2× usual Itoigawa Itoigawa, 17 May: 10.8 µg/m³, 1.1× usual Itoigawa, 18 May: 14.9 µg/m³, 1.6× usual Itoigawa, 19 May: 13.2 µg/m³, 1.4× usual Itoigawa, 20 May: 22.7 µg/m³, 2.4× usual Itoigawa, 21 May: 26.8 µg/m³, 2.8× usual Itoigawa, 22 May: 12.4 µg/m³, 1.3× usual Itoigawa, 23 May: 11.0 µg/m³, 1.2× usual Itoigawa, 24 May: 13.0 µg/m³, 1.4× usual Hashima Hashima, 17 May: 6.9 µg/m³, 0.8× usual Hashima, 18 May: 13.8 µg/m³, 1.6× usual Hashima, 19 May: 18.8 µg/m³, 2.2× usual Hashima, 20 May: 23.9 µg/m³, 2.8× usual Hashima, 21 May: 26.7 µg/m³, 3.1× usual Hashima, 22 May: 5.6 µg/m³, 0.7× usual Hashima, 23 May: 12.1 µg/m³, 1.4× usual Hashima, 24 May: 14.7 µg/m³, 1.7× usual Matsutō Matsutō, 17 May: 8.4 µg/m³, 1.0× usual Matsutō, 18 May: 11.4 µg/m³, 1.4× usual Matsutō, 19 May: 13.0 µg/m³, 1.6× usual Matsutō, 20 May: 18.0 µg/m³, 2.2× usual Matsutō, 21 May: 26.6 µg/m³, 3.2× usual Matsutō, 22 May: 13.6 µg/m³, 1.7× usual Matsutō, 23 May: 8.1 µg/m³, 1.0× usual Matsutō, 24 May: 9.7 µg/m³, 1.2× usual Onomichi Onomichi, 17 May: 11.5 µg/m³, 1.0× usual Onomichi, 18 May: 11.8 µg/m³, 1.0× usual Onomichi, 19 May: 21.5 µg/m³, 1.9× usual Onomichi, 20 May: 23.8 µg/m³, 2.1× usual Onomichi, 21 May: 26.6 µg/m³, 2.4× usual Onomichi, 22 May: 8.1 µg/m³, 0.7× usual Onomichi, 23 May: 14.0 µg/m³, 1.2× usual Onomichi, 24 May: 12.6 µg/m³, 1.1× usual Takayama Takayama, 17 May: 6.3 µg/m³, 0.8× usual Takayama, 18 May: 10.8 µg/m³, 1.4× usual Takayama, 19 May: 7.8 µg/m³, 1.0× usual Takayama, 20 May: 18.6 µg/m³, 2.4× usual Takayama, 21 May: 26.5 µg/m³, 3.5× usual Takayama, 22 May: 5.4 µg/m³, 0.7× usual Takayama, 23 May: 10.7 µg/m³, 1.4× usual Takayama, 24 May: 10.9 µg/m³, 1.4× usual Akishima Akishima, 17 May: 7.9 µg/m³, 1.1× usual Akishima, 18 May: 10.5 µg/m³, 1.4× usual Akishima, 19 May: 13.0 µg/m³, 1.8× usual Akishima, 20 May: 21.0 µg/m³, 2.8× usual Akishima, 21 May: 26.4 µg/m³, 3.6× usual Akishima, 22 May: 11.5 µg/m³, 1.6× usual Akishima, 23 May: 9.1 µg/m³, 1.2× usual Akishima, 24 May: 10.2 µg/m³, 1.4× usual Yokota Yokota, 17 May: 8.4 µg/m³, 1.0× usual Yokota, 18 May: 10.7 µg/m³, 1.3× usual Yokota, 19 May: 14.1 µg/m³, 1.7× usual Yokota, 20 May: 21.5 µg/m³, 2.6× usual Yokota, 21 May: 26.1 µg/m³, 3.1× usual Yokota, 22 May: 12.5 µg/m³, 1.5× usual Yokota, 23 May: 9.0 µg/m³, 1.1× usual Yokota, 24 May: 11.0 µg/m³, 1.3× usual Saku Saku, 17 May: 6.4 µg/m³, 1.0× usual Saku, 18 May: 7.5 µg/m³, 1.1× usual Saku, 19 May: 7.0 µg/m³, 1.1× usual Saku, 20 May: 18.2 µg/m³, 2.8× usual Saku, 21 May: 26.0 µg/m³, 3.9× usual Saku, 22 May: 17.5 µg/m³, 2.7× usual Saku, 23 May: 10.1 µg/m³, 1.5× usual Saku, 24 May: 8.7 µg/m³, 1.3× usual 17 May 18 19 20 21 22 23 24 The 60 cities with the highest readings of 103, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Saku Nagano, Japan 1 21 May 6.6 3.9× Yamanashi Yamanashi, Japan 2 21 May 8.1 3.9× Nasukarasuyama Tochigi, Japan 1 21 May 6.4 3.9× Suwa Nagano, Japan 1 21 May 7.0 3.9× Ebina Kanagawa, Japan 1 20 May 7.1 3.8× Ono Fukui, Japan 1 21 May 7.1 3.8× Sabae Fukui, Japan 1 21 May 7.9 3.8× Sakura Chiba, Japan 1 20 May 6.8 3.8× Chigasaki Kanagawa, Japan 1 20 May 7.8 3.7× Yokohama Kanagawa, Japan 1 20 May 7.3 3.6× Akishima Tokyo, Japan 1 21 May 7.4 3.6× Imaichi Tochigi, Japan 1 21 May 7.6 3.6× Hadano Kanagawa, Japan 1 20 May 7.1 3.5× Matsumoto Nagano, Japan 1 21 May 7.2 3.5× Shirakawa Fukushima, Japan 1 21 May 7.6 3.5× Ōgaki Gifu, Japan 1 21 May 7.1 3.5× Azamino Kanagawa, Japan 1 20 May 7.3 3.5× Ayase Kanagawa, Japan 2 20 May 9.6 3.5× Iida Nagano, Japan 1 21 May 7.2 3.5× Takayama Gifu, Japan 1 21 May 7.6 3.5× Yamato Kanagawa, Japan 1 20 May 7.4 3.5× Chikuma Nagano, Japan 1 21 May 7.2 3.5× Kaga Ishikawa, Japan 1 21 May 8.1 3.4× Ogawamachi Saitama, Japan 1 21 May 7.3 3.4× Atsugi Kanagawa, Japan 1 20 May 7.6 3.4× Ōme Tokyo, Japan 1 21 May 8.1 3.4× Ayabe Kyoto, Japan 1 20 May 8.6 3.4× Maizuru Kyoto, Japan 1 20 May 7.9 3.4× Nagahama Shiga, Japan 1 20 May 8.3 3.4× Hachiōji Tokyo, Japan 1 21 May 7.6 3.4× Yaita Tochigi, Japan 1 21 May 7.7 3.4× Fukuchiyama Kyoto, Japan 1 20 May 8.6 3.3× Mikuni Fukui, Japan 1 21 May 8.6 3.3× Tonami Toyama, Japan 1 21 May 8.1 3.3× Ono Hyōgo, Japan 1 20 May 8.1 3.3× Hannō Saitama, Japan 1 21 May 8.4 3.3× Chichibu Saitama, Japan 1 21 May 8.7 3.3× Matsutō Ishikawa, Japan 1 21 May 8.2 3.2× Aihara Kanagawa, Japan 1 21 May 8.0 3.2× Sano Tochigi, Japan 1 21 May 8.5 3.2× Komatsu Ishikawa, Japan 1 21 May 8.0 3.2× Youkaichi Shiga, Japan 1 20 May 7.8 3.2× Tatsuno Hyōgo, Japan 1 20 May 8.1 3.2× Tottori-shi Tottori, Japan 1 21 May 9.6 3.2× Tomioka Gunma, Japan 1 21 May 9.6 3.2× Nakanojō Gunma, Japan 1 21 May 8.6 3.2× Higashinozoe Hyōgo, Japan 1 20 May 8.3 3.2× Toyama Toyama, Japan 1 21 May 8.6 3.2× Kiryū Gunma, Japan 1 21 May 9.3 3.2× Morohongō Saitama, Japan 1 21 May 8.9 3.2× Tsu Mie, Japan 1 20 May 8.2 3.1× Yokota Tokyo, Japan 1 21 May 8.3 3.1× Minamirinkan Kanagawa, Japan 1 20 May 8.4 3.1× Ageo Saitama, Japan 1 21 May 8.7 3.1× Inabe Mie, Japan 1 20 May 8.1 3.1× Nagoya Aichi, Japan 1 21 May 8.1 3.1× Kuwana Mie, Japan 1 21 May 8.1 3.1× Hashima Gifu, Japan 1 21 May 8.6 3.1× Kurayoshi Tottori, Japan 1 19 May 10.2 3.1× Fukui-shi Fukui, Japan 1 21 May 8.4 3.1× Kōnosu Saitama, Japan 1 21 May 8.2 3.0× Ōtsuki Yamanashi, Japan 2 21 May 10.8 3.0× Miyazu Kyoto, Japan 1 20 May 8.6 3.0× Minawa Kanagawa, Japan 1 21 May 8.6 3.0× Shibukawa Gunma, Japan 1 21 May 9.8 3.0× Numata Gunma, Japan 1 21 May 8.5 3.0× Gifu Gifu, Japan 1 21 May 8.5 3.0× Tsuchiura Ibaraki, Japan 1 21 May 8.4 3.0× Iruma Saitama, Japan 1 21 May 9.1 3.0× Higashi-Matsuyama Saitama, Japan 1 21 May 8.7 3.0× Sandachō Hyōgo, Japan 1 20 May 8.8 3.0× Niiza Saitama, Japan 1 21 May 8.5 3.0× Yorii Saitama, Japan 1 21 May 9.4 3.0× Menuma Saitama, Japan 1 21 May 9.3 3.0× Sakado Saitama, Japan 1 21 May 8.7 3.0× Honjō Saitama, Japan 1 21 May 8.5 3.0× Kodamachō-kodamaminami Saitama, Japan 1 21 May 10.0 3.0× Mima Tokushima, Japan 2 21 May 9.6 2.9× Kameyama Mie, Japan 1 20 May 8.9 2.9× Toyooka Hyōgo, Japan 1 21 May 8.7 2.9× Kakogawachō-honmachi Hyōgo, Japan 1 20 May 9.0 2.9× Ikedachō Tokushima, Japan 2 20 May 10.3 2.9× Tatebayashi Gunma, Japan 1 21 May 9.1 2.8× Asaka Saitama, Japan 1 21 May 8.8 2.8× Takashima Shiga, Japan 1 20 May 9.1 2.8× Sagae Yamagata, Japan 1 21 May 9.0 2.8× Kofu Yamanashi, Japan 2 21 May 10.1 2.8× Itoigawa Niigata, Japan 1 21 May 9.5 2.8× Nantan Kyoto, Japan 1 20 May 9.4 2.8× Takehara Hiroshima, Japan 1 21 May 9.2 2.8× Imizu Toyama, Japan 1 21 May 9.1 2.8× Saijō Ehime, Japan 1 21 May 11.9 2.8× Igusa Saitama, Japan 1 21 May 9.1 2.8× Toki Gifu, Japan 1 21 May 9.3 2.7× Uozu Toyama, Japan 1 21 May 10.0 2.7× Kashiwara Nara, Japan 1 20 May 9.6 2.7× Nyūzen Toyama, Japan 1 21 May 9.6 2.7× Jōetsu Niigata, Japan 1 21 May 10.7 2.7× Gyōda Saitama, Japan 1 21 May 10.3 2.6× Owariasahi Aichi, Japan 1 21 May 10.3 2.5× Niihama Ehime, Japan 1 21 May 11.9 2.5× Shikokuchūō Ehime, Japan 1 21 May 11.6 2.4× Onomichi Hiroshima, Japan 1 21 May 11.3 2.4×
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in Japan
Number 10 of 27 episodes in Japan since our records began, by cities reached.
Japan, June and July 2025 508 Japan and South Korea, March 2025 454 Japan and South Korea, March 2026 305 Japan and South Korea, January 2025 274 Japan and South Korea, February and March 2025 192 Japan, July 2026 172 Japan, November 2023 131 Japan, August 2025 126 Japan, January and February 2025 110 Japan, May 2025 103 Japan, March 2025 92 Japan and South Korea, April 2025 86 Bars: cities reached; colour: the level of the episode's highest daily reading. All 27 .
Use this page SmogRank, Japan, May 2025: 103 cities with PM2.5 at twice their usual or more, 20 to 21 May 2025, smogrank.com/episodes/2025-05-japan (accessed 2 October 2026).
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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms .
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes . Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.
