SmogRank / Episodes / Japan
Japan, April 2025
For 2 days, from 19 to 20 April 2025, 34 cities in Japan had PM2.5 at least twice their usual for the time of year. The worst reading was Hiratsuka, Kanagawa, Japan: 51.2 µg/m³ on 20 April, about 6.1× its usual 8.4.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 34 in 1 country
Days 2 19 to 20 April 2025
Worst day 19 April 33 cities counted
Furthest above usual 6.1× Hiratsuka
Day by day
Play 19 April 33 cities at twice their usual or more
Kiryū Numata Ōta Ashikaga Shibukawa Honjō Tatebayashi Imaichi Nakanojō Hanyū Tochigi Tomioka Ogawamachi Koga Chichibu Utsunomiya Kaminokawa Kawagoe Minamiuonuma Sayama Kasukabe Iruma Chikusei Saitama Mooka Bandō Ōme Tokorozawa Shimo-tsuma Niiza Yokota Asaka Higashimurayama Higashikurume Koshigaya Akishima Kodaira Jōsō Kawaguchi Saku Sōka Nasukarasuyama Hachiōji Fuchū Nasushiobara Aihara Tokyo Noborito Kashiwa Suzaka Ōtsuki Matsudo Kasama Nagaoka Azamino Naka Machida Toride Tsuchiura Ishioka Kamagaya Minamirinkan Urayasu Yamato Atsugi Nagano Ayase Hitachiomiya Inzai Shirakawa Narashino Aizu-Wakamatsu Yachiyo Ebina Yokohama Hadano Mito Ajiki Inashiki Chikuma Fujiyoshida Fujisawa Jōetsu Chigasaki Minamiashigara Minami-Alps Shirone Yotsukaidō Chiba Sakura Kamakura Hitachi-Naka Niitsu-honchō Gotemba Maki Narita Odawara Hokota Ichihara Yokosuka Kisarazu Kimitsu Okaya Kameda-honchō Sodegaura Matsumoto Yachimata Hitachi Kurihama Sawara Kōriyama Niigata Shibata Susono Miura Ōami Tōgane Atami Kashima-shi Kitaibaraki Yokoshiba Fuji Numazu Omigawa Mobara Ina Sōsa Itoigawa Kamisu Yonezawa Minamibōsō Tateyama Ōhara Nagai Katsuura Sado Choshi Iida Shizuoka Nyūzen Shimoda Uozu Namerikawa Fujieda Shiroishi Yamagata Minami-Sōma Shimada Kakuda Sōma Toyama Sagae Imizu Kikugawa Kakegawa Higashine Tsuruoka Fukuroi Takaoka Natori-shi Hamakita Himimachi Iwata Sendai Tonami Nanao Shonai Hamamatsu Shinshiro Oyabe Shinjō Sakata Tagajō-shi Yoshioka Anamizu Hakui Seto Tsubata Kosai Matsushima Toyota Toyohashi Inuyama Owariasahi Nisshin Okazaki Ōsaki Higashimatsushima Nonoichi Kanazawa Gamagōri Anjō Matsutō Wakuya Chiryū Nagoya Ichinomiya Kariya Nishio Kurihara Tōkai Ama Komatsu Hekinan Ono Tome Handa Minamichita Tokoname Kaga Kaminoma Kuwana Ichinoseki Inabe Yokkaichi Fukui-shi Mikuni Sabae Suzuka Toba Nagahama Kesennuma Hikone Shima Kameyama Ise Tsu Saikū Tsuruga Matsusaka Youkaichi Takashima Ōmihachiman Kōka Iga Ueno-ebisumachi Kitahama Kusatsu Obama Nabari Ōtsu Kyoto Uji Jōyō Kizugawa Sugai Kōtari Yawata Tenri Kameoka Hirakata Ikoma Hōryūji Takatsuki Kashihara-shi Nantan Kashiwara Maizuru Yono Higashiosaka Yao Habikino Toyonaka Miyazu Tondabayashichō Osaka Ayabe Sayama Kawachi-Nagano Amagasaki Hashimoto Sakai Takarazuka Kyōtango Fukuchiyama Nishinomiya Izumi Sandachō Kishiwada Tanba Kinokawa Kobe Izumisano Toyooka Sennan Iwade Nishiwaki Ono Akashi Kainan Minato Higashinozoe Kakogawachō-honmachi Himeji Sumoto Ikaruga Tatsuno Aioi Tottori-shi Kariya Narutochō-mitsuishi Bizen Fukushima Gyōda Tahara Iwanuma Igusa Kodamachō-kodamaminami Kofu Yorii Ishinomaki Ageo Kazo Sakado Higashi-Matsuyama Misato, Saitama Hannō Kōnosu Kukichūō Morohongō Kumagaya Menuma Sakai-nakajima Minawa Sano Iwaki Noda Oyama Fujinomiya Kanuma Ueda Yaita Suwa Yamanashi Izunokuni Hiratsuka 16 Apr 17 18 19 20 21 22 23 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
Yamanashi Yamanashi, 16 April: no reading Yamanashi, 17 April: no reading Yamanashi, 18 April: 32.3 µg/m³, 3.4× usual Yamanashi, 19 April: 30.3 µg/m³, 3.2× usual Yamanashi, 20 April: 25.5 µg/m³, 2.7× usual Yamanashi, 21 April: no reading Yamanashi, 22 April: no reading Yamanashi, 23 April: no reading Ishinomaki Ishinomaki, 16 April: 6.8 µg/m³, 0.6× usual Ishinomaki, 17 April: 19.4 µg/m³, 1.6× usual Ishinomaki, 18 April: 25.6 µg/m³, 2.2× usual Ishinomaki, 19 April: 29.0 µg/m³, 2.5× usual Ishinomaki, 20 April: 17.2 µg/m³, 1.5× usual Ishinomaki, 21 April: 10.8 µg/m³, 0.9× usual Ishinomaki, 22 April: 13.4 µg/m³, 1.1× usual Ishinomaki, 23 April: 12.7 µg/m³, 1.1× usual Menuma Menuma, 16 April: 6.3 µg/m³, 0.6× usual Menuma, 17 April: 14.6 µg/m³, 1.4× usual Menuma, 18 April: 21.2 µg/m³, 2.1× usual Menuma, 19 April: 28.0 µg/m³, 2.7× usual Menuma, 20 April: 26.0 µg/m³, 2.5× usual Menuma, 21 April: 8.9 µg/m³, 0.9× usual Menuma, 22 April: 14.0 µg/m³, 1.4× usual Menuma, 23 April: 8.5 µg/m³, 0.8× usual Minawa Minawa, 16 April: 7.0 µg/m³, 0.7× usual Minawa, 17 April: 14.5 µg/m³, 1.5× usual Minawa, 18 April: 20.5 µg/m³, 2.1× usual Minawa, 19 April: 27.6 µg/m³, 2.8× usual Minawa, 20 April: 17.7 µg/m³, 1.8× usual Minawa, 21 April: 8.5 µg/m³, 0.9× usual Minawa, 22 April: 10.9 µg/m³, 1.1× usual Minawa, 23 April: 4.7 µg/m³, 0.5× usual Kodamachō-kodamamin… Kodamachō-kodamaminami, 16 April: 5.9 µg/m³, 0.5× usual Kodamachō-kodamaminami, 17 April: 14.0 µg/m³, 1.3× usual Kodamachō-kodamaminami, 18 April: 24.2 µg/m³, 2.2× usual Kodamachō-kodamaminami, 19 April: 27.1 µg/m³, 2.4× usual Kodamachō-kodamaminami, 20 April: 26.0 µg/m³, 2.3× usual Kodamachō-kodamaminami, 21 April: 7.8 µg/m³, 0.7× usual Kodamachō-kodamaminami, 22 April: 14.5 µg/m³, 1.3× usual Kodamachō-kodamaminami, 23 April: 9.7 µg/m³, 0.9× usual Oyama Oyama, 16 April: 4.8 µg/m³, 0.5× usual Oyama, 17 April: 14.8 µg/m³, 1.6× usual Oyama, 18 April: 19.9 µg/m³, 2.1× usual Oyama, 19 April: 27.0 µg/m³, 2.9× usual Oyama, 20 April: 20.5 µg/m³, 2.2× usual Oyama, 21 April: 8.0 µg/m³, 0.9× usual Oyama, 22 April: 13.4 µg/m³, 1.4× usual Oyama, 23 April: 5.0 µg/m³, 0.5× usual Iwaki Iwaki, 16 April: 6.1 µg/m³, 0.7× usual Iwaki, 17 April: 11.4 µg/m³, 1.2× usual Iwaki, 18 April: 21.6 µg/m³, 2.3× usual Iwaki, 19 April: 26.7 µg/m³, 2.9× usual Iwaki, 20 April: 20.8 µg/m³, 2.3× usual Iwaki, 21 April: 8.8 µg/m³, 1.0× usual Iwaki, 22 April: 12.7 µg/m³, 1.4× usual Iwaki, 23 April: 9.3 µg/m³, 1.0× usual Kumagaya Kumagaya, 16 April: 6.1 µg/m³, 0.6× usual Kumagaya, 17 April: 14.0 µg/m³, 1.4× usual Kumagaya, 18 April: 19.7 µg/m³, 2.0× usual Kumagaya, 19 April: 26.6 µg/m³, 2.7× usual Kumagaya, 20 April: 25.5 µg/m³, 2.6× usual Kumagaya, 21 April: 8.1 µg/m³, 0.8× usual Kumagaya, 22 April: 13.2 µg/m³, 1.3× usual Kumagaya, 23 April: 7.1 µg/m³, 0.7× usual Gyōda Gyōda, 16 April: 7.4 µg/m³, 0.6× usual Gyōda, 17 April: 15.7 µg/m³, 1.4× usual Gyōda, 18 April: 21.2 µg/m³, 1.8× usual Gyōda, 19 April: 26.6 µg/m³, 2.3× usual Gyōda, 20 April: 24.9 µg/m³, 2.2× usual Gyōda, 21 April: 9.4 µg/m³, 0.8× usual Gyōda, 22 April: 14.8 µg/m³, 1.3× usual Gyōda, 23 April: 8.7 µg/m³, 0.8× usual Sano Sano, 16 April: 6.8 µg/m³, 0.7× usual Sano, 17 April: 16.1 µg/m³, 1.7× usual Sano, 18 April: 21.9 µg/m³, 2.3× usual Sano, 19 April: 26.4 µg/m³, 2.8× usual Sano, 20 April: 22.2 µg/m³, 2.4× usual Sano, 21 April: 9.1 µg/m³, 1.0× usual Sano, 22 April: 13.9 µg/m³, 1.5× usual Sano, 23 April: 5.7 µg/m³, 0.6× usual Igusa Igusa, 16 April: 5.8 µg/m³, 0.5× usual Igusa, 17 April: 14.0 µg/m³, 1.3× usual Igusa, 18 April: 22.9 µg/m³, 2.0× usual Igusa, 19 April: 26.4 µg/m³, 2.4× usual Igusa, 20 April: 25.9 µg/m³, 2.3× usual Igusa, 21 April: 8.1 µg/m³, 0.7× usual Igusa, 22 April: 13.7 µg/m³, 1.2× usual Igusa, 23 April: 7.1 µg/m³, 0.6× usual Higashi-Matsuyama Higashi-Matsuyama, 16 April: 6.8 µg/m³, 0.7× usual Higashi-Matsuyama, 17 April: 13.9 µg/m³, 1.4× usual Higashi-Matsuyama, 18 April: 21.5 µg/m³, 2.1× usual Higashi-Matsuyama, 19 April: 26.3 µg/m³, 2.6× usual Higashi-Matsuyama, 20 April: 24.6 µg/m³, 2.4× usual Higashi-Matsuyama, 21 April: 8.5 µg/m³, 0.8× usual Higashi-Matsuyama, 22 April: 13.6 µg/m³, 1.3× usual Higashi-Matsuyama, 23 April: 7.4 µg/m³, 0.7× usual Izunokuni Izunokuni, 16 April: 5.2 µg/m³, 0.7× usual Izunokuni, 17 April: 14.4 µg/m³, 1.9× usual Izunokuni, 18 April: 21.3 µg/m³, 2.9× usual Izunokuni, 19 April: 26.2 µg/m³, 3.5× usual Izunokuni, 20 April: 9.1 µg/m³, 1.2× usual Izunokuni, 21 April: 8.1 µg/m³, 1.1× usual Izunokuni, 22 April: 8.9 µg/m³, 1.2× usual Izunokuni, 23 April: 3.1 µg/m³, 0.4× usual Ueda Ueda, 16 April: 5.6 µg/m³, 0.6× usual Ueda, 17 April: 14.9 µg/m³, 1.7× usual Ueda, 18 April: 21.5 µg/m³, 2.5× usual Ueda, 19 April: 26.1 µg/m³, 3.0× usual Ueda, 20 April: 19.2 µg/m³, 2.2× usual Ueda, 21 April: 7.6 µg/m³, 0.9× usual Ueda, 22 April: 12.5 µg/m³, 1.4× usual Ueda, 23 April: 6.0 µg/m³, 0.7× usual Kazo Kazo, 16 April: 5.7 µg/m³, 0.5× usual Kazo, 17 April: 14.6 µg/m³, 1.4× usual Kazo, 18 April: 21.0 µg/m³, 2.0× usual Kazo, 19 April: 26.1 µg/m³, 2.5× usual Kazo, 20 April: 21.2 µg/m³, 2.0× usual Kazo, 21 April: 8.4 µg/m³, 0.8× usual Kazo, 22 April: 13.0 µg/m³, 1.3× usual Kazo, 23 April: 7.7 µg/m³, 0.7× usual Morohongō Morohongō, 16 April: 4.8 µg/m³, 0.5× usual Morohongō, 17 April: 13.1 µg/m³, 1.3× usual Morohongō, 18 April: 22.4 µg/m³, 2.3× usual Morohongō, 19 April: 26.0 µg/m³, 2.6× usual Morohongō, 20 April: 25.0 µg/m³, 2.5× usual Morohongō, 21 April: 7.7 µg/m³, 0.8× usual Morohongō, 22 April: 13.9 µg/m³, 1.4× usual Morohongō, 23 April: 6.8 µg/m³, 0.7× usual Sakai-nakajima Sakai-nakajima, 16 April: 5.8 µg/m³, 0.6× usual Sakai-nakajima, 17 April: 14.7 µg/m³, 1.4× usual Sakai-nakajima, 18 April: 20.3 µg/m³, 2.0× usual Sakai-nakajima, 19 April: 25.8 µg/m³, 2.5× usual Sakai-nakajima, 20 April: 27.6 µg/m³, 2.7× usual Sakai-nakajima, 21 April: 7.4 µg/m³, 0.7× usual Sakai-nakajima, 22 April: 14.0 µg/m³, 1.4× usual Sakai-nakajima, 23 April: 7.9 µg/m³, 0.8× usual Misato, Saitama Misato, Saitama, 16 April: 6.3 µg/m³, 0.6× usual Misato, Saitama, 17 April: 14.8 µg/m³, 1.5× usual Misato, Saitama, 18 April: 21.3 µg/m³, 2.1× usual Misato, Saitama, 19 April: 25.8 µg/m³, 2.6× usual Misato, Saitama, 20 April: 13.6 µg/m³, 1.3× usual Misato, Saitama, 21 April: 10.6 µg/m³, 1.0× usual Misato, Saitama, 22 April: 14.9 µg/m³, 1.5× usual Misato, Saitama, 23 April: 7.3 µg/m³, 0.7× usual Kukichūō Kukichūō, 16 April: 6.8 µg/m³, 0.7× usual Kukichūō, 17 April: 14.5 µg/m³, 1.5× usual Kukichūō, 18 April: 20.4 µg/m³, 2.0× usual Kukichūō, 19 April: 25.7 µg/m³, 2.6× usual Kukichūō, 20 April: 20.5 µg/m³, 2.1× usual Kukichūō, 21 April: 8.2 µg/m³, 0.8× usual Kukichūō, 22 April: 14.5 µg/m³, 1.5× usual Kukichūō, 23 April: 7.3 µg/m³, 0.7× usual Yorii Yorii, 16 April: 6.2 µg/m³, 0.6× usual Yorii, 17 April: 14.2 µg/m³, 1.3× usual Yorii, 18 April: 22.7 µg/m³, 2.1× usual Yorii, 19 April: 25.7 µg/m³, 2.4× usual Yorii, 20 April: 25.3 µg/m³, 2.4× usual Yorii, 21 April: 7.8 µg/m³, 0.7× usual Yorii, 22 April: 13.9 µg/m³, 1.3× usual Yorii, 23 April: 9.1 µg/m³, 0.9× usual Fujinomiya Fujinomiya, 16 April: 7.6 µg/m³, 0.9× usual Fujinomiya, 17 April: 14.4 µg/m³, 1.7× usual Fujinomiya, 18 April: 23.7 µg/m³, 2.8× usual Fujinomiya, 19 April: 25.6 µg/m³, 3.0× usual Fujinomiya, 20 April: 9.6 µg/m³, 1.1× usual Fujinomiya, 21 April: 8.1 µg/m³, 0.9× usual Fujinomiya, 22 April: 7.2 µg/m³, 0.8× usual Fujinomiya, 23 April: 5.1 µg/m³, 0.6× usual Tahara Tahara, 16 April: 10.2 µg/m³, 0.9× usual Tahara, 17 April: 15.6 µg/m³, 1.4× usual Tahara, 18 April: 20.9 µg/m³, 1.9× usual Tahara, 19 April: 25.6 µg/m³, 2.3× usual Tahara, 20 April: 14.6 µg/m³, 1.3× usual Tahara, 21 April: 10.1 µg/m³, 0.9× usual Tahara, 22 April: 11.0 µg/m³, 1.0× usual Tahara, 23 April: 10.1 µg/m³, 0.9× usual Kofu Kofu, 16 April: 9.1 µg/m³, 0.9× usual Kofu, 17 April: 18.5 µg/m³, 1.7× usual Kofu, 18 April: 24.5 µg/m³, 2.3× usual Kofu, 19 April: 25.5 µg/m³, 2.4× usual Kofu, 20 April: 19.1 µg/m³, 1.8× usual Kofu, 21 April: 8.4 µg/m³, 0.8× usual Kofu, 22 April: 10.6 µg/m³, 1.0× usual Kofu, 23 April: 3.4 µg/m³, 0.3× usual Kanuma Kanuma, 16 April: 6.6 µg/m³, 0.8× usual Kanuma, 17 April: 14.2 µg/m³, 1.7× usual Kanuma, 18 April: 19.5 µg/m³, 2.3× usual Kanuma, 19 April: 25.4 µg/m³, 3.0× usual Kanuma, 20 April: 23.6 µg/m³, 2.8× usual Kanuma, 21 April: 8.6 µg/m³, 1.0× usual Kanuma, 22 April: 12.6 µg/m³, 1.5× usual Kanuma, 23 April: 5.4 µg/m³, 0.6× usual Fukushima Fukushima, 16 April: no reading Fukushima, 17 April: 20.7 µg/m³, 1.7× usual Fukushima, 18 April: 17.3 µg/m³, 1.4× usual Fukushima, 19 April: 25.4 µg/m³, 2.0× usual Fukushima, 20 April: 22.4 µg/m³, 1.8× usual Fukushima, 21 April: no reading Fukushima, 22 April: 13.0 µg/m³, 1.0× usual Fukushima, 23 April: 9.2 µg/m³, 0.7× usual Ageo Ageo, 16 April: 6.1 µg/m³, 0.6× usual Ageo, 17 April: 14.9 µg/m³, 1.5× usual Ageo, 18 April: 21.1 µg/m³, 2.1× usual Ageo, 19 April: 25.3 µg/m³, 2.5× usual Ageo, 20 April: 20.5 µg/m³, 2.0× usual Ageo, 21 April: 9.6 µg/m³, 1.0× usual Ageo, 22 April: 13.9 µg/m³, 1.4× usual Ageo, 23 April: 7.5 µg/m³, 0.7× usual Kōnosu Kōnosu, 16 April: 6.0 µg/m³, 0.6× usual Kōnosu, 17 April: 14.9 µg/m³, 1.5× usual Kōnosu, 18 April: 20.4 µg/m³, 2.1× usual Kōnosu, 19 April: 25.2 µg/m³, 2.6× usual Kōnosu, 20 April: 24.4 µg/m³, 2.5× usual Kōnosu, 21 April: 8.7 µg/m³, 0.9× usual Kōnosu, 22 April: 13.0 µg/m³, 1.3× usual Kōnosu, 23 April: 6.6 µg/m³, 0.7× usual Yaita Yaita, 16 April: 5.4 µg/m³, 0.7× usual Yaita, 17 April: 12.9 µg/m³, 1.6× usual Yaita, 18 April: 18.8 µg/m³, 2.3× usual Yaita, 19 April: 25.1 µg/m³, 3.0× usual Yaita, 20 April: 23.1 µg/m³, 2.8× usual Yaita, 21 April: 9.4 µg/m³, 1.1× usual Yaita, 22 April: 12.0 µg/m³, 1.4× usual Yaita, 23 April: 5.4 µg/m³, 0.7× usual Hannō Hannō, 16 April: 4.8 µg/m³, 0.5× usual Hannō, 17 April: 13.1 µg/m³, 1.3× usual Hannō, 18 April: 22.1 µg/m³, 2.3× usual Hannō, 19 April: 25.1 µg/m³, 2.6× usual Hannō, 20 April: 23.0 µg/m³, 2.3× usual Hannō, 21 April: 8.1 µg/m³, 0.8× usual Hannō, 22 April: 12.9 µg/m³, 1.3× usual Hannō, 23 April: 8.0 µg/m³, 0.8× usual Iwanuma Iwanuma, 16 April: 4.9 µg/m³, 0.5× usual Iwanuma, 17 April: 15.3 µg/m³, 1.5× usual Iwanuma, 18 April: 18.8 µg/m³, 1.8× usual Iwanuma, 19 April: 25.1 µg/m³, 2.4× usual Iwanuma, 20 April: 19.9 µg/m³, 1.9× usual Iwanuma, 21 April: 10.6 µg/m³, 1.0× usual Iwanuma, 22 April: 13.2 µg/m³, 1.3× usual Iwanuma, 23 April: 12.6 µg/m³, 1.2× usual Suwa Suwa, 16 April: 6.0 µg/m³, 0.8× usual Suwa, 17 April: 18.2 µg/m³, 2.3× usual Suwa, 18 April: 24.3 µg/m³, 3.0× usual Suwa, 19 April: 25.0 µg/m³, 3.1× usual Suwa, 20 April: 16.2 µg/m³, 2.0× usual Suwa, 21 April: 7.4 µg/m³, 0.9× usual Suwa, 22 April: 10.8 µg/m³, 1.4× usual Suwa, 23 April: 3.1 µg/m³, 0.4× usual Noda Noda, 16 April: 5.8 µg/m³, 0.7× usual Noda, 17 April: 15.2 µg/m³, 1.8× usual Noda, 18 April: 21.8 µg/m³, 2.6× usual Noda, 19 April: 25.0 µg/m³, 2.9× usual Noda, 20 April: 12.4 µg/m³, 1.5× usual Noda, 21 April: 8.2 µg/m³, 1.0× usual Noda, 22 April: 13.6 µg/m³, 1.6× usual Noda, 23 April: 6.9 µg/m³, 0.8× usual Sakado Sakado, 16 April: 6.5 µg/m³, 0.6× usual Sakado, 17 April: 14.4 µg/m³, 1.4× usual Sakado, 18 April: 21.7 µg/m³, 2.1× usual Sakado, 19 April: 25.0 µg/m³, 2.5× usual Sakado, 20 April: 23.5 µg/m³, 2.3× usual Sakado, 21 April: 8.3 µg/m³, 0.8× usual Sakado, 22 April: 13.3 µg/m³, 1.3× usual Sakado, 23 April: 7.2 µg/m³, 0.7× usual Hiratsuka Hiratsuka, 16 April: 6.2 µg/m³, 0.7× usual Hiratsuka, 17 April: 12.0 µg/m³, 1.4× usual Hiratsuka, 18 April: 18.5 µg/m³, 2.2× usual Hiratsuka, 19 April: 22.6 µg/m³, 2.7× usual Hiratsuka, 20 April: 51.2 µg/m³, 6.1× usual Hiratsuka, 21 April: 8.0 µg/m³, 1.0× usual Hiratsuka, 22 April: 11.0 µg/m³, 1.3× usual Hiratsuka, 23 April: 5.6 µg/m³, 0.7× usual 16 Apr 17 18 19 20 21 22 23 Every counted city, 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
Hiratsuka Kanagawa, Japan 1 20 April 8.4 6.1× Izunokuni Shizuoka, Japan 1 19 April 7.4 3.5× Yamanashi Yamanashi, Japan 2 18 April 9.6 3.4× Suwa Nagano, Japan 1 19 April 8.0 3.1× Yaita Tochigi, Japan 1 19 April 8.3 3.0× Ueda Nagano, Japan 1 19 April 8.7 3.0× Kanuma Tochigi, Japan 1 19 April 8.5 3.0× Fujinomiya Shizuoka, Japan 1 19 April 8.6 3.0× Noda Chiba, Japan 1 19 April 8.5 2.9× Oyama Tochigi, Japan 1 19 April 9.3 2.9× Iwaki Fukushima, Japan 1 19 April 9.2 2.9× Minawa Kanagawa, Japan 1 19 April 9.7 2.8× Sano Tochigi, Japan 1 19 April 9.4 2.8× Menuma Saitama, Japan 2 19 April 10.3 2.7× Sakai-nakajima Gunma, Japan 2 20 April 10.3 2.7× Kumagaya Saitama, Japan 2 19 April 10.0 2.7× Morohongō Saitama, Japan 2 19 April 9.9 2.6× Higashi-Matsuyama Saitama, Japan 1 19 April 10.1 2.6× Kōnosu Saitama, Japan 1 19 April 9.8 2.6× Kukichūō Saitama, Japan 1 19 April 10.0 2.6× Hannō Saitama, Japan 1 19 April 9.8 2.6× Misato, Saitama Saitama, Japan 1 19 April 10.1 2.6× Kazo Saitama, Japan 1 19 April 10.4 2.5× Ageo Saitama, Japan 1 19 April 10.1 2.5× Sakado Saitama, Japan 1 19 April 10.1 2.5× Ishinomaki Miyagi, Japan 1 19 April 11.8 2.5× Iwanuma Miyagi, Japan 1 19 April 10.3 2.4× Yorii Saitama, Japan 2 19 April 10.6 2.4× Kodamachō-kodamaminami Saitama, Japan 2 19 April 11.2 2.4× Kofu Yamanashi, Japan 1 19 April 10.6 2.4× Igusa Saitama, Japan 2 19 April 11.2 2.4× Gyōda Saitama, Japan 1 19 April 11.5 2.3× Tahara Aichi, Japan 1 19 April 11.2 2.3× Fukushima Fukushima, Japan 1 19 April 12.4 2.0×
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 17 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 Japan, April 2025 34 Bars: cities reached; colour: the level of the episode's highest daily reading. All 27 .
Use this page SmogRank, Japan, April 2025: 34 cities with PM2.5 at twice their usual or more, 19 to 20 April 2025, smogrank.com/episodes/2025-04-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.
