SmogRank / Episodes / Taiwan
Taiwan, January 2025
For 2 days, from 21 to 22 January 2025, 22 cities in Taiwan had PM2.5 at least twice their usual for the time of year. The worst reading was Yuanlin, Taiwan: 55.3 µg/m³ on 22 January, about 2.6× its usual 21.0.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 22 in 1 country
Days 2 21 to 22 January 2025
Worst day 22 January 18 cities counted
Furthest above usual 2.8× Magong
Day by day
Play 22 January 18 cities at twice their usual or more
Erlin Zhushan Erlun Puli Taibao Xinying Zhudong Hualien City Tainan Yilan Taitung Fengshan Kaohsiung Sanzhi Chaozhou Keelung Hengchun Jincheng Ishigaki Nantou Yongkang Chiayi City Neili Xizhi Beigang Taoyuan Xizhou Miaoli Toufen New Taipei City Shulin Douliu Taipei Hsinchu Daxi Zhubei Taichung Yuanlin Changhua Buzi Magong 18 Jan 19 20 21 22 23 24 25 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
Yongkang Yongkang, 18 January: 27.2 µg/m³, 1.2× usual Yongkang, 19 January: 23.3 µg/m³, 1.0× usual Yongkang, 20 January: 30.8 µg/m³, 1.4× usual Yongkang, 21 January: 44.7 µg/m³, 2.0× usual Yongkang, 22 January: 37.9 µg/m³, 1.7× usual Yongkang, 23 January: 41.0 µg/m³, 1.8× usual Yongkang, 24 January: 25.1 µg/m³, 1.1× usual Yongkang, 25 January: 36.8 µg/m³, 1.7× usual Magong Magong, 18 January: 17.3 µg/m³, 1.3× usual Magong, 19 January: 12.0 µg/m³, 0.9× usual Magong, 20 January: 20.7 µg/m³, 1.5× usual Magong, 21 January: 38.7 µg/m³, 2.8× usual Magong, 22 January: 25.1 µg/m³, 1.8× usual Magong, 23 January: 12.7 µg/m³, 0.9× usual Magong, 24 January: 13.8 µg/m³, 1.0× usual Magong, 25 January: 20.0 µg/m³, 1.5× usual Beigang Beigang, 18 January: 19.7 µg/m³, 1.1× usual Beigang, 19 January: 18.3 µg/m³, 1.0× usual Beigang, 20 January: 26.7 µg/m³, 1.5× usual Beigang, 21 January: 37.6 µg/m³, 2.1× usual Beigang, 22 January: 35.7 µg/m³, 2.0× usual Beigang, 23 January: 34.0 µg/m³, 1.9× usual Beigang, 24 January: 23.0 µg/m³, 1.3× usual Beigang, 25 January: 25.7 µg/m³, 1.5× usual Changhua Changhua, 18 January: 15.1 µg/m³, 0.9× usual Changhua, 19 January: 14.2 µg/m³, 0.9× usual Changhua, 20 January: 20.2 µg/m³, 1.2× usual Changhua, 21 January: 31.0 µg/m³, 1.9× usual Changhua, 22 January: 44.1 µg/m³, 2.7× usual Changhua, 23 January: 19.9 µg/m³, 1.2× usual Changhua, 24 January: 17.1 µg/m³, 1.1× usual Changhua, 25 January: 20.5 µg/m³, 1.3× usual Xizhi Xizhi, 18 January: 11.1 µg/m³, 0.9× usual Xizhi, 19 January: 17.1 µg/m³, 1.4× usual Xizhi, 20 January: 21.4 µg/m³, 1.7× usual Xizhi, 21 January: 26.0 µg/m³, 2.1× usual Xizhi, 22 January: 21.0 µg/m³, 1.7× usual Xizhi, 23 January: 22.0 µg/m³, 1.8× usual Xizhi, 24 January: 13.0 µg/m³, 1.0× usual Xizhi, 25 January: 15.1 µg/m³, 1.2× usual Taipei Taipei, 18 January: 9.5 µg/m³, 0.8× usual Taipei, 19 January: 15.9 µg/m³, 1.3× usual Taipei, 20 January: 18.9 µg/m³, 1.6× usual Taipei, 21 January: 25.2 µg/m³, 2.1× usual Taipei, 22 January: 28.4 µg/m³, 2.3× usual Taipei, 23 January: 20.6 µg/m³, 1.7× usual Taipei, 24 January: 12.1 µg/m³, 1.0× usual Taipei, 25 January: 14.8 µg/m³, 1.2× usual New Taipei City New Taipei City, 18 January: 9.0 µg/m³, 0.7× usual New Taipei City, 19 January: 14.0 µg/m³, 1.1× usual New Taipei City, 20 January: 19.4 µg/m³, 1.6× usual New Taipei City, 21 January: 25.2 µg/m³, 2.0× usual New Taipei City, 22 January: 27.6 µg/m³, 2.2× usual New Taipei City, 23 January: 18.9 µg/m³, 1.5× usual New Taipei City, 24 January: 11.1 µg/m³, 0.9× usual New Taipei City, 25 January: 14.7 µg/m³, 1.2× usual Yuanlin Yuanlin, 18 January: 21.5 µg/m³, 1.0× usual Yuanlin, 19 January: 14.7 µg/m³, 0.7× usual Yuanlin, 20 January: 23.3 µg/m³, 1.1× usual Yuanlin, 21 January: 35.4 µg/m³, 1.7× usual Yuanlin, 22 January: 55.3 µg/m³, 2.6× usual Yuanlin, 23 January: 25.3 µg/m³, 1.2× usual Yuanlin, 24 January: 20.9 µg/m³, 1.0× usual Yuanlin, 25 January: 22.9 µg/m³, 1.1× usual Douliu Douliu, 18 January: 27.5 µg/m³, 1.1× usual Douliu, 19 January: 20.9 µg/m³, 0.9× usual Douliu, 20 January: 33.6 µg/m³, 1.4× usual Douliu, 21 January: 44.3 µg/m³, 1.8× usual Douliu, 22 January: 54.9 µg/m³, 2.3× usual Douliu, 23 January: 35.7 µg/m³, 1.5× usual Douliu, 24 January: 26.3 µg/m³, 1.1× usual Douliu, 25 January: 34.2 µg/m³, 1.4× usual Chiayi City Chiayi City, 18 January: 25.5 µg/m³, 1.1× usual Chiayi City, 19 January: 19.3 µg/m³, 0.8× usual Chiayi City, 20 January: 30.9 µg/m³, 1.3× usual Chiayi City, 21 January: no reading Chiayi City, 22 January: 49.4 µg/m³, 2.1× usual Chiayi City, 23 January: 45.6 µg/m³, 1.9× usual Chiayi City, 24 January: 32.9 µg/m³, 1.4× usual Chiayi City, 25 January: 39.0 µg/m³, 1.6× usual Buzi Buzi, 18 January: 15.7 µg/m³, 0.9× usual Buzi, 19 January: 13.7 µg/m³, 0.8× usual Buzi, 20 January: 18.7 µg/m³, 1.1× usual Buzi, 21 January: 31.6 µg/m³, 1.9× usual Buzi, 22 January: 47.0 µg/m³, 2.8× usual Buzi, 23 January: 19.3 µg/m³, 1.2× usual Buzi, 24 January: 17.3 µg/m³, 1.0× usual Buzi, 25 January: 20.4 µg/m³, 1.2× usual Taichung Taichung, 18 January: 17.2 µg/m³, 1.0× usual Taichung, 19 January: 14.0 µg/m³, 0.8× usual Taichung, 20 January: 18.8 µg/m³, 1.0× usual Taichung, 21 January: 29.7 µg/m³, 1.7× usual Taichung, 22 January: 46.5 µg/m³, 2.6× usual Taichung, 23 January: 22.5 µg/m³, 1.3× usual Taichung, 24 January: 17.0 µg/m³, 0.9× usual Taichung, 25 January: 18.3 µg/m³, 1.0× usual Nantou Nantou, 18 January: 18.8 µg/m³, 1.0× usual Nantou, 19 January: 16.3 µg/m³, 0.8× usual Nantou, 20 January: 18.3 µg/m³, 0.9× usual Nantou, 21 January: 31.8 µg/m³, 1.6× usual Nantou, 22 January: 39.3 µg/m³, 2.0× usual Nantou, 23 January: 31.9 µg/m³, 1.6× usual Nantou, 24 January: 20.7 µg/m³, 1.1× usual Nantou, 25 January: 20.9 µg/m³, 1.1× usual Daxi Daxi, 18 January: 13.1 µg/m³, 0.9× usual Daxi, 19 January: 15.8 µg/m³, 1.1× usual Daxi, 20 January: 17.5 µg/m³, 1.2× usual Daxi, 21 January: 23.2 µg/m³, 1.6× usual Daxi, 22 January: 34.9 µg/m³, 2.4× usual Daxi, 23 January: 22.7 µg/m³, 1.6× usual Daxi, 24 January: 13.8 µg/m³, 1.0× usual Daxi, 25 January: 14.8 µg/m³, 1.0× usual Miaoli Miaoli, 18 January: 12.9 µg/m³, 0.9× usual Miaoli, 19 January: 14.9 µg/m³, 1.0× usual Miaoli, 20 January: 17.5 µg/m³, 1.2× usual Miaoli, 21 January: 26.7 µg/m³, 1.8× usual Miaoli, 22 January: 32.7 µg/m³, 2.2× usual Miaoli, 23 January: 17.9 µg/m³, 1.2× usual Miaoli, 24 January: 16.3 µg/m³, 1.1× usual Miaoli, 25 January: 17.9 µg/m³, 1.2× usual Hsinchu Hsinchu, 18 January: 15.0 µg/m³, 1.1× usual Hsinchu, 19 January: 15.3 µg/m³, 1.1× usual Hsinchu, 20 January: 20.7 µg/m³, 1.5× usual Hsinchu, 21 January: 24.0 µg/m³, 1.7× usual Hsinchu, 22 January: 32.5 µg/m³, 2.4× usual Hsinchu, 23 January: 18.4 µg/m³, 1.3× usual Hsinchu, 24 January: 14.7 µg/m³, 1.1× usual Hsinchu, 25 January: 17.4 µg/m³, 1.3× usual Xizhou Xizhou, 18 January: 16.4 µg/m³, 1.1× usual Xizhou, 19 January: 12.3 µg/m³, 0.8× usual Xizhou, 20 January: 14.1 µg/m³, 1.0× usual Xizhou, 21 January: 20.6 µg/m³, 1.4× usual Xizhou, 22 January: 32.0 µg/m³, 2.2× usual Xizhou, 23 January: 20.4 µg/m³, 1.4× usual Xizhou, 24 January: 16.8 µg/m³, 1.2× usual Xizhou, 25 January: 15.3 µg/m³, 1.1× usual Neili Neili, 18 January: 13.0 µg/m³, 0.9× usual Neili, 19 January: 15.3 µg/m³, 1.0× usual Neili, 20 January: 20.3 µg/m³, 1.4× usual Neili, 21 January: 25.3 µg/m³, 1.7× usual Neili, 22 January: 31.8 µg/m³, 2.1× usual Neili, 23 January: 18.8 µg/m³, 1.3× usual Neili, 24 January: 13.4 µg/m³, 0.9× usual Neili, 25 January: 18.1 µg/m³, 1.2× usual Toufen Toufen, 18 January: 13.7 µg/m³, 0.9× usual Toufen, 19 January: 15.5 µg/m³, 1.1× usual Toufen, 20 January: 18.9 µg/m³, 1.3× usual Toufen, 21 January: 26.3 µg/m³, 1.8× usual Toufen, 22 January: 31.4 µg/m³, 2.2× usual Toufen, 23 January: 16.1 µg/m³, 1.1× usual Toufen, 24 January: 14.9 µg/m³, 1.0× usual Toufen, 25 January: 16.4 µg/m³, 1.1× usual Zhubei Zhubei, 18 January: 13.2 µg/m³, 1.1× usual Zhubei, 19 January: 13.8 µg/m³, 1.1× usual Zhubei, 20 January: 20.9 µg/m³, 1.7× usual Zhubei, 21 January: 24.3 µg/m³, 2.0× usual Zhubei, 22 January: 31.1 µg/m³, 2.5× usual Zhubei, 23 January: 16.3 µg/m³, 1.3× usual Zhubei, 24 January: 13.5 µg/m³, 1.1× usual Zhubei, 25 January: 16.6 µg/m³, 1.3× usual Shulin Shulin, 18 January: 9.8 µg/m³, 0.8× usual Shulin, 19 January: 15.9 µg/m³, 1.3× usual Shulin, 20 January: 17.9 µg/m³, 1.4× usual Shulin, 21 January: 22.9 µg/m³, 1.8× usual Shulin, 22 January: 29.5 µg/m³, 2.3× usual Shulin, 23 January: 21.4 µg/m³, 1.7× usual Shulin, 24 January: 11.0 µg/m³, 0.9× usual Shulin, 25 January: 14.4 µg/m³, 1.1× usual Taoyuan Taoyuan, 18 January: 6.6 µg/m³, 0.5× usual Taoyuan, 19 January: 13.0 µg/m³, 1.1× usual Taoyuan, 20 January: 15.9 µg/m³, 1.3× usual Taoyuan, 21 January: 22.3 µg/m³, 1.8× usual Taoyuan, 22 January: 26.5 µg/m³, 2.2× usual Taoyuan, 23 January: 14.8 µg/m³, 1.2× usual Taoyuan, 24 January: 9.9 µg/m³, 0.8× usual Taoyuan, 25 January: 13.3 µg/m³, 1.1× usual 18 Jan 19 20 21 22 23 24 25 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
Magong Taiwan 1 21 January 13.6 2.8× Buzi Taiwan 1 22 January 16.6 2.8× Changhua Taiwan 2 22 January 16.2 2.7× Yuanlin Taiwan 1 22 January 21.0 2.6× Taichung Taiwan 1 22 January 18.0 2.6× Zhubei Taiwan 1 22 January 12.4 2.5× Daxi Taiwan 1 22 January 14.3 2.4× Hsinchu Taiwan 1 22 January 13.8 2.4× Taipei Taiwan 2 22 January 12.1 2.3× Shulin Taipei, Taiwan 1 22 January 12.7 2.3× Douliu Taiwan 1 22 January 24.1 2.3× New Taipei City Taipei, Taiwan 2 22 January 12.5 2.2× Xizhou Taiwan 1 22 January 14.5 2.2× Miaoli Taiwan 1 22 January 14.9 2.2× Toufen Taiwan 1 22 January 14.5 2.2× Taoyuan Taiwan 1 22 January 12.3 2.2× Neili Taiwan 1 22 January 14.8 2.1× Beigang Taiwan 1 21 January 17.6 2.1× Xizhi Taipei, Taiwan 1 21 January 12.4 2.1× Chiayi City Taiwan 1 22 January 23.8 2.1× Yongkang Taiwan 1 21 January 22.2 2.0× Nantou Taiwan 1 22 January 19.6 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 Taiwan
Number 2 of 8 episodes in Taiwan since our records began, by cities reached.
Bars: cities reached; colour: the level of the episode's highest daily reading.
Use this page SmogRank, Taiwan, January 2025: 22 cities with PM2.5 at twice their usual or more, 21 to 22 January 2025, smogrank.com/episodes/2025-01-taiwan-2 (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.
