Air quality comparison · Taiwan, 174 km apart
Kaohsiung vs Taichung Air quality index (AQI) today
Kaohsiung has cleaner air than Taichung right now: AQI 62 (Moderate) against 68 (Moderate).
Both sit in the same EPA band, so the health advice is the same for each today. But over the past 7 days, on modeled daily averages, Taichung averaged AQI 100 against 105, and it was the cleaner of the two on 5 of those days. Taichung has lost more forest since 2001. Kaohsiung has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Kaohsiung62Taichung68
Head to head
Kaohsiung vs Taichung at a glance
Kaohsiung is ahead on 5 of 6 measures, and Taichung on 1. The better figure in each row is marked.
| Kaohsiung | Taichung | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 62 (better) | 68 |
| PM2.5Fine particles, µg/m³. | 15 (better) | 18 |
| Past week's averageUS AQI, 7 days. | 105 | 100 (better) |
| Forest lost since 2001Within 10 km of the center. | 12 ha (better) | 201 ha |
| Tree coverWithin 2 km of the center. | 10.8% (better) | 9.9% |
| Trees still neededTo reach a healthy canopy. | 60.0K (better) | 63.1K |
Air quality today
What is the air like in Kaohsiung and Taichung right now?
Kaohsiung has cleaner air than Taichung right now: AQI 62 (Moderate) against 68 (Moderate). PM2.5 is setting the index in both.
Taichung's PM2.5 is about 1.2× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
KaohsiungTaichung
Concentrations at the same moment as the index above, for the pollutants both places report. Lower is better. The dark marks on the PM2.5 and PM10 rows show the WHO's 24-hour guidelines (15 and 45 µg/m³).
Kaohsiung: Ground station · 高雄市 - 前鎮, 1.4 km away · median of 7 stations. Data: OpenAQ · Taiwan, Ministry of Environment, Taiwan (Open Government Data License 1.0).
Taichung: Ground station · 臺中市 - 臺灣大道, 3.1 km away · median of 4 stations. Data: OpenAQ · Taiwan, Ministry of Environment, Taiwan (Open Government Data License 1.0).
The past week
Which had cleaner air over the past 7 days?
But over the past 7 days, on modeled daily averages, Taichung averaged AQI 100 against 105, and it was the cleaner of the two on 5 of those days. A single reading can catch a city on a bad afternoon; the week says whether it was the weather or the place.
- Cleaner days
- Kaohsiung2Taichung5
- Average AQI
- Kaohsiung105Taichung100
- Worst day, AQI
- Kaohsiung138Taichung131
The daily numbers (7 days)
| Day | Kaohsiung | Taichung |
|---|---|---|
| Nov 5 | 117 | 114 |
| Nov 6 | 138 | 131 |
| Nov 7 | 121 | 114 |
| Nov 8 | 95 | 109 |
| Nov 9 | 99 | 69 |
| Nov 10 | 70 | 66 |
| Nov 11 | 96 | 99 |
Daily averages from the CAMS atmospheric model for both places, so the week compares like with like. They can differ from today's reading at the top of the page wherever that comes from a ground station.
What it means today
Is it safe to go outside in Kaohsiung and Taichung today?
Unusually sensitive people should consider limiting long outdoor exertion. Both are in the same EPA band today (Moderate), so the advice is the same.
Exercise outdoors
Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
Fine to open; close them if you are sensitive to pollution.
Masks
Not needed for most people.
Air purifier
Worth running if you are sensitive.
Against everywhere else
How do Kaohsiung and Taichung compare with the rest of the world?
Right now Kaohsiung's air is cleaner than 46% of the 5,420 places Airleaf tracks, and Taichung's is cleaner than 39%. Within Taiwan, that is 24% and 12% of its 18 measured places.
Cleaner air than…
- Kaohsiung
- Beats 46%
- Taichung
- Beats 39%
More tree cover than…
- Kaohsiung
- Beats 23%
- Taichung
- Beats 21%
Includes model estimates as well as station readings, so it can differ from our most polluted and cleanest air rankings, which use station readings only.
Deforestation · 2001–2025
Which has lost more forest, Kaohsiung or Taichung?
Taichung has lost more: about 201 ha of forest within 10 km of its center from 2001 to 2025, against 12 ha around Kaohsiung. 197 ha of that was cleared for good, for farms, mines or towns.
Measured within 10 km of each center, from the yearly satellite maps of forest loss: a wider circle than the one for tree cover, because forest is usually lost at a city's edges.
Worst year: 2024, with 3 ha lost.
Worst year: 2012, with 28 ha lost.
| Kaohsiung | Taichung | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 12 ha (better) | 201 ha |
| Share of its forestOf what it had in 2000. | under 1% (better) | 4% |
| Cleared for goodTurned into farms, mines or towns. | 9 ha (better) | 197 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (60%) | Towns and roads (58%) |
Satellite timelapses
Watch both change, year by year
A clear satellite photo a year of the land around each city. Press play, turn on the forest cleared since the first year, or drag the before and after.
Kaohsiung
2017: satellite photo from January 2017 of a 5 × 5 km area in the city center.
Taichung
2017: satellite photo from January 2017 of a 5 × 5 km area about 7 km east of the city center.
Trees
Which has more trees, Kaohsiung or Taichung?
Kaohsiung has more tree cover: 10.8% of the land within 2 km of its center against 9.9% around Taichung, or about 33,760 trees against 31,102.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Kaohsiung | Taichung | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 33.8K (better) | 31.1K |
| Trees still neededTo reach the target. Fewer is better. | 60.0K (better) | 63.1K |
| CO₂ absorbed each yearBy the trees already standing. | 743K kg (better) | 684K kg |
Tree cover on the satellite image
The same 2 km radius around each center, with the tree cover the satellite found marked on it.
Reading these numbers
How this comparison is made
Air quality index
The US EPA index, computed from current pollutant concentrations: ground stations where a place has them nearby, and the CAMS atmospheric model everywhere else. It moves hour to hour, so it is a snapshot rather than a verdict on either place. The guideline marks are from the WHO's 2021 air quality guidelines.
Trees and forest
Tree cover is the share of ground under canopy within 2 km of each center, read from Sentinel-2 satellite imagery at 10 m detail. It measures that circle, not the whole municipality, which is what makes the two comparable. Forest loss comes from the University of Maryland's Global Forest Change maps.
More on the method on the About Airleaf page.
Frequently asked
Kaohsiung vs Taichung: your questions answered
Is Kaohsiung cleaner than Taichung?
On air quality, yes, right now: Kaohsiung reads AQI 62 against 68, a gap of 6 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. But over the past 7 days, on modeled daily averages, Taichung averaged AQI 100 against 105, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in Kaohsiung and Taichung today?
The advice is the same for both today. Unusually sensitive people should consider limiting long outdoor exertion. Kaohsiung reads AQI 62 and Taichung reads AQI 68.
Which has lost more forest, Kaohsiung or Taichung?
Taichung has lost more: about 201 ha of forest within 10 km of its center from 2001 to 2025, against 12 ha around Kaohsiung. 197 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Kaohsiung or Taichung?
Kaohsiung has more tree cover: 10.8% of the land within 2 km of its center against 9.9% around Taichung, or about 33,760 trees against 31,102. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Kaohsiung and Taichung need?
Kaohsiung needs about 60,017 more to reach its canopy target of 30%, and Taichung about 63,146 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Kaohsiung and Taichung measured the same way?
The method is the same: the US EPA index for air, and Sentinel-2 satellite imagery at 10 m detail over an identical radius for trees. Both readings come from nearby ground stations. Nothing is adjusted for population, city limits or climate.
How often does the Kaohsiung vs Taichung comparison update?
The air readings refresh about once an hour, and each reading's local time is shown at the top of the page. Tree cover comes from the latest clear satellite image of each area (Sep 18, 2026 and Sep 16, 2026), and the forest figures are published yearly.
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