SmogRank / Episodes / Taiwan
Taiwan, 17 February 2025
For 1 day, on 17 February 2025, 21 cities in Taiwan had PM2.5 at least twice their usual for the time of year. The worst reading was Jincheng, Fukien, Taiwan: 47.5 µg/m³ on 17 February, about 2.1× its usual 22.9.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 21 in 1 country
Days 1 17 February 2025
Worst day 17 February 21 cities counted
Furthest above usual 6.2× Sanzhi
Day by day
Play 17 February 21 cities at twice their usual or more
Buzi Yuanlin Xizhou Taichung Nantou Douliu Zhushan Miaoli Taibao Puli Zhudong Yongkang Tainan Hualien City Fengshan Kaohsiung Chaozhou Taitung Hengchun Ishigaki Toufen Daxi Erlin Beigang Erlun Chiayi City Jincheng Hsinchu Changhua Neili Xinying Shulin Zhubei Taipei Magong Taoyuan New Taipei City Xizhi Keelung Yilan Sanzhi 14 Feb 15 16 17 18 19 20 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
Jincheng Jincheng, 14 February: 24.1 µg/m³ Jincheng, 15 February: 27.3 µg/m³ Jincheng, 16 February: 46.2 µg/m³ Jincheng, 17 February: 47.5 µg/m³, 2.1× its usual 22.9 Jincheng, 18 February: 23.3 µg/m³ Jincheng, 19 February: 17.8 µg/m³ Jincheng, 20 February: 14.3 µg/m³ Chiayi City Chiayi City, 14 February: 18.9 µg/m³ Chiayi City, 15 February: 27.9 µg/m³ Chiayi City, 16 February: 36.5 µg/m³ Chiayi City, 17 February: 45.7 µg/m³, 2.1× its usual 21.8 Chiayi City, 18 February: 39.0 µg/m³ Chiayi City, 19 February: 21.5 µg/m³ Chiayi City, 20 February: 34.0 µg/m³ Xinying Xinying, 14 February: 19.3 µg/m³ Xinying, 15 February: 25.6 µg/m³ Xinying, 16 February: 33.8 µg/m³ Xinying, 17 February: 45.1 µg/m³, 2.4× its usual 19.1 Xinying, 18 February: 33.9 µg/m³ Xinying, 19 February: 19.4 µg/m³ Xinying, 20 February: 29.0 µg/m³ Erlun Erlun, 14 February: 16.4 µg/m³ Erlun, 15 February: 25.4 µg/m³ Erlun, 16 February: 31.5 µg/m³ Erlun, 17 February: 42.4 µg/m³, 2.1× its usual 19.9 Erlun, 18 February: 27.0 µg/m³ Erlun, 19 February: 17.1 µg/m³ Erlun, 20 February: 21.3 µg/m³ Beigang Beigang, 14 February: 15.4 µg/m³ Beigang, 15 February: 23.3 µg/m³ Beigang, 16 February: 29.3 µg/m³ Beigang, 17 February: 39.9 µg/m³, 2.1× its usual 18.8 Beigang, 18 February: 28.1 µg/m³ Beigang, 19 February: 15.5 µg/m³ Beigang, 20 February: 23.0 µg/m³ Magong Magong, 14 February: 16.8 µg/m³ Magong, 15 February: 11.7 µg/m³ Magong, 16 February: 13.9 µg/m³ Magong, 17 February: 38.2 µg/m³, 2.8× its usual 13.8 Magong, 18 February: 16.5 µg/m³ Magong, 19 February: 17.4 µg/m³ Magong, 20 February: 13.2 µg/m³ Erlin Erlin, 14 February: 11.1 µg/m³ Erlin, 15 February: 19.0 µg/m³ Erlin, 16 February: 24.8 µg/m³ Erlin, 17 February: 38.2 µg/m³, 2.1× its usual 18.4 Erlin, 18 February: 19.0 µg/m³ Erlin, 19 February: 13.0 µg/m³ Erlin, 20 February: 15.8 µg/m³ Xizhi Xizhi, 14 February: 8.5 µg/m³ Xizhi, 15 February: 15.9 µg/m³ Xizhi, 16 February: 22.4 µg/m³ Xizhi, 17 February: 37.5 µg/m³, 3.0× its usual 12.7 Xizhi, 18 February: 12.0 µg/m³ Xizhi, 19 February: 11.3 µg/m³ Xizhi, 20 February: 10.3 µg/m³ Keelung Keelung, 14 February: 6.5 µg/m³ Keelung, 15 February: 10.4 µg/m³ Keelung, 16 February: 18.1 µg/m³ Keelung, 17 February: 36.8 µg/m³, 3.1× its usual 11.9 Keelung, 18 February: 9.7 µg/m³ Keelung, 19 February: 9.4 µg/m³ Keelung, 20 February: 8.8 µg/m³ Taipei Taipei, 14 February: 7.8 µg/m³ Taipei, 15 February: 16.9 µg/m³ Taipei, 16 February: 21.4 µg/m³ Taipei, 17 February: 36.8 µg/m³, 2.8× its usual 13.0 Taipei, 18 February: 12.3 µg/m³ Taipei, 19 February: 11.0 µg/m³ Taipei, 20 February: 10.9 µg/m³ New Taipei City New Taipei City, 14 February: 6.4 µg/m³ New Taipei City, 15 February: 16.0 µg/m³ New Taipei City, 16 February: 20.6 µg/m³ New Taipei City, 17 February: 36.0 µg/m³, 2.9× its usual 12.3 New Taipei City, 18 February: 10.5 µg/m³ New Taipei City, 19 February: 8.7 µg/m³ New Taipei City, 20 February: 9.9 µg/m³ Neili Neili, 14 February: 9.0 µg/m³ Neili, 15 February: 26.9 µg/m³ Neili, 16 February: 25.3 µg/m³ Neili, 17 February: 36.0 µg/m³, 2.4× its usual 15.1 Neili, 18 February: 12.1 µg/m³ Neili, 19 February: 8.2 µg/m³ Neili, 20 February: 13.5 µg/m³ Zhubei Zhubei, 14 February: 7.8 µg/m³ Zhubei, 15 February: 25.1 µg/m³ Zhubei, 16 February: 25.3 µg/m³ Zhubei, 17 February: 34.8 µg/m³, 2.7× its usual 12.8 Zhubei, 18 February: 10.3 µg/m³ Zhubei, 19 February: 6.6 µg/m³ Zhubei, 20 February: 13.7 µg/m³ Taoyuan Taoyuan, 14 February: 6.6 µg/m³ Taoyuan, 15 February: 22.1 µg/m³ Taoyuan, 16 February: 21.5 µg/m³ Taoyuan, 17 February: 33.5 µg/m³, 2.9× its usual 11.7 Taoyuan, 18 February: 10.8 µg/m³ Taoyuan, 19 February: 8.4 µg/m³ Taoyuan, 20 February: 10.9 µg/m³ Changhua Changhua, 14 February: 9.8 µg/m³ Changhua, 15 February: 19.1 µg/m³ Changhua, 16 February: 23.3 µg/m³ Changhua, 17 February: 33.5 µg/m³, 2.2× its usual 15.4 Changhua, 18 February: 20.7 µg/m³ Changhua, 19 February: 12.3 µg/m³ Changhua, 20 February: 15.8 µg/m³ Sanzhi Sanzhi, 14 February: 0.5 µg/m³ Sanzhi, 15 February: 2.7 µg/m³ Sanzhi, 16 February: 6.8 µg/m³ Sanzhi, 17 February: 33.3 µg/m³, 6.2× its usual 5.4 Sanzhi, 18 February: 0.8 µg/m³ Sanzhi, 19 February: 1.5 µg/m³ Sanzhi, 20 February: 2.9 µg/m³ Shulin Shulin, 14 February: 5.5 µg/m³ Shulin, 15 February: 20.5 µg/m³ Shulin, 16 February: 24.5 µg/m³ Shulin, 17 February: 33.1 µg/m³, 2.6× its usual 12.9 Shulin, 18 February: 12.6 µg/m³ Shulin, 19 February: 6.5 µg/m³ Shulin, 20 February: 8.4 µg/m³ Hsinchu Hsinchu, 14 February: 15.1 µg/m³ Hsinchu, 15 February: 27.9 µg/m³ Hsinchu, 16 February: 24.5 µg/m³ Hsinchu, 17 February: 30.6 µg/m³, 2.2× its usual 14.2 Hsinchu, 18 February: 11.9 µg/m³ Hsinchu, 19 February: 6.9 µg/m³ Hsinchu, 20 February: 16.5 µg/m³ Daxi Daxi, 14 February: 6.3 µg/m³ Daxi, 15 February: 23.3 µg/m³ Daxi, 16 February: 24.9 µg/m³ Daxi, 17 February: 30.0 µg/m³, 2.1× its usual 14.0 Daxi, 18 February: 12.0 µg/m³ Daxi, 19 February: 6.6 µg/m³ Daxi, 20 February: 14.4 µg/m³ Yilan Yilan, 14 February: 3.9 µg/m³ Yilan, 15 February: 4.1 µg/m³ Yilan, 16 February: 13.0 µg/m³ Yilan, 17 February: 29.4 µg/m³, 3.4× its usual 8.6 Yilan, 18 February: 14.8 µg/m³ Yilan, 19 February: 7.5 µg/m³ Yilan, 20 February: 8.1 µg/m³ Toufen Toufen, 14 February: 30.7 µg/m³ Toufen, 15 February: 25.7 µg/m³ Toufen, 16 February: 25.0 µg/m³ Toufen, 17 February: 28.0 µg/m³, 2.0× its usual 13.7 Toufen, 18 February: 14.1 µg/m³ Toufen, 19 February: 7.4 µg/m³ Toufen, 20 February: 17.3 µg/m³ 14 Feb 15 16 17 18 19 20 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
Sanzhi Taipei, Taiwan 1 17 February 5.4 6.2× Yilan Taiwan 1 17 February 8.6 3.4× Keelung Taiwan 1 17 February 11.9 3.1× Xizhi Taipei, Taiwan 1 17 February 12.7 3.0× New Taipei City Taipei, Taiwan 1 17 February 12.3 2.9× Taoyuan Taiwan 1 17 February 11.7 2.9× Magong Taiwan 1 17 February 13.8 2.8× Taipei Taiwan 1 17 February 13.0 2.8× Zhubei Taiwan 1 17 February 12.8 2.7× Shulin Taipei, Taiwan 1 17 February 12.9 2.6× Xinying Taiwan 1 17 February 19.1 2.4× Neili Taiwan 1 17 February 15.1 2.4× Changhua Taiwan 1 17 February 15.4 2.2× Hsinchu Taiwan 1 17 February 14.2 2.2× Jincheng Fukien, Taiwan 1 17 February 22.9 2.1× Chiayi City Taiwan 1 17 February 21.8 2.1× Erlun Taiwan 1 17 February 19.9 2.1× Beigang Taiwan 1 17 February 18.8 2.1× Erlin Taiwan 1 17 February 18.4 2.1× Daxi Taiwan 1 17 February 14.0 2.1× Toufen Taiwan 1 17 February 13.7 2.0×
Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.
Against other episodes in Taiwan
Number 3 of 12 episodes in Taiwan since our records began, by cities reached.
Taiwan, 26 to 28 February 2025 24 Taiwan, 21 to 22 January 2025 22 Taiwan, 17 February 2025 21 Taiwan, November 2024 21 Taiwan, March 2024 20 Taiwan, December 2024 18 Taiwan, 28 November 2025 17 Taiwan, May 2024 16 Taiwan, 14 to 15 January 2025 14 Taiwan, February 2026 13 Taiwan, March 2025 13 Taiwan, 25 November 2025 12 Bars: cities reached; colour: the level of the episode's highest daily reading.
Use this page SmogRank, Taiwan, 17 February 2025: 21 cities with PM2.5 at twice their usual or more, 17 February 2025, smogrank.com/episodes/2025-02-17-taiwan (accessed 4 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.
