Country comparison · 263 cities measured
Japan vs South Korea Air quality index (AQI) and deforestation
Japan has cleaner air than South Korea right now: its cities average AQI 48 against 80.
At ground stations alone, which measure rather than estimate, the averages are Japan 65 (39 cities) and South Korea 80 (56 cities). Japan has lost more forest since 2001. South Korea has more tree cover in its cities.
Average of 207 cities
AQI 48
Good
Cleaner on average
- At ground stations
- AQI 65
- Tree cover
- 16.4%
- Forest lost since 2001
- 1.02 million ha
Average of 56 cities
AQI 80
Moderate
Cleaner on average
- At ground stations
- AQI 80
- Tree cover
- 28.4%
- Forest lost since 2001
- 436,000 ha
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Japan48South Korea80
Head to head
Japan vs South Korea at a glance
Japan is ahead on 4 of 6 measures, and South Korea on 2. The better figure in each row is marked.
| Japan | South Korea | |
|---|---|---|
| Average air qualityUS AQI, all measured cities. | 48 (better) | 80 |
| At ground stationsCities with a current station reading. | 65 (better) | 80 |
| Cities over AQI 100Not fine for sensitive groups. | 6% (better) | 13% |
| Forest lost since 2001The whole country. | 1.02 million ha | 436,000 ha (better) |
| Share of its forest lostOf what it had in 2000. | 3.9% (better) | 8.2% |
| Average tree coverAcross its measured cities. | 16.4% | 28.4% (better) |
Air quality today
Is Japan cleaner than South Korea?
On air quality, yes, right now. Japan has cleaner air than South Korea right now: its cities average AQI 48 against 80.
At ground stations alone, which measure rather than estimate, the averages are Japan 65 (39 cities) and South Korea 80 (56 cities).
6% of the measured cities in Japan are over AQI 100 today, the point where the air stops being fine for sensitive groups, against 13% in South Korea.
How each country's cities split across the air quality bands
Japan
- Good107 (52%)
- Moderate87 (42%)
- Unhealthy for sensitive groups13 (6%)
South Korea
- Moderate49 (88%)
- Unhealthy for sensitive groups7 (13%)
Every measured city, including model estimates where no ground station is near.
Against everywhere else
How do Japan and South Korea compare with other countries?
Right now the cities of Japan average cleaner air than 56% of the 171 countries Airleaf has enough cities to average, and those of South Korea than 14%.
Cleaner air than…
- Japan
- Beats 56%
- South Korea
- Beats 14%
More tree cover than…
- Japan
- Beats 33%
- South Korea
- Beats 64%
Deforestation · 2001–2025
Which country has lost more forest, Japan or South Korea?
Japan has lost more: about 1.02 million ha of forest from 2001 to 2025, against 436,000 ha in South Korea, or 2.3 times as much. 108,000 ha of Japan's was cleared for good, for farms, mines or towns; the rest burned, was logged or can grow back.
The whole country, from the yearly satellite maps of forest loss: unlike the city averages above, this counts every forest, not just the land around cities.
Worst year: 2016, with 54,800 ha lost.
Worst year: 2025, with 87,000 ha lost.
| Japan | South Korea | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 1.02 million ha | 436,000 ha (better) |
| Share of its forestOf what it had in 2000. | 3.9% (better) | 8.2% |
| Cleared for goodTurned into farms, mines or towns. | 108,000 ha | 67,300 ha (better) |
| Recent trend2021–2025 against the five years before. | Holding steady | Speeding up |
| Main known cause | Logging (87%) | Logging (70%) |
Trees
Which country has more tree cover, Japan or South Korea?
South Korea does: its measured cities average 28.4% tree cover against 16.4%, a gap of 12.0 percentage points.
| Japan | South Korea | |
|---|---|---|
| Trees standingSummed across measured cities. | 10.2M (better) | 4.8M |
| Cities below their targetShort of the canopy target. | 82% | 57% (better) |
| Trees still neededTo reach those targets. | 9.8M | 1.3M (better) |
Behind the averages
The cities behind Japan and South Korea
An average says nothing about how far apart the best and worst places are. These are the measured cities at each end.
Reading these numbers
What a country average is, and is not
It is a mean of cities
Not a national statistic. Each figure is the average across the cities Airleaf has measured: 207 in Japan and 56 in South Korea, each read over the same 2 km radius, on the US EPA index. Rural land and unmeasured towns are not in it.
Coverage shapes the number
A country measured mostly in its capital reads differently from one measured across dozens of towns. Japan rests on 207 cities against 56, so its average is the steadier of the two. Forest figures come from the University of Maryland's Global Forest Change maps.
Frequently asked
Japan vs South Korea: your questions answered
Is Japan cleaner than South Korea?
On air quality, yes, right now: Japan's cities average AQI 48 against 80 on the US EPA index. These are live readings averaged across cities, so the gap moves with the weather. At ground stations alone, which measure rather than estimate, the averages are Japan 65 (39 cities) and South Korea 80 (56 cities).
Which country has lost more forest, Japan or South Korea?
Japan has lost more: about 1.02 million ha of forest from 2001 to 2025, against 436,000 ha in South Korea, or 2.3 times as much. 108,000 ha of Japan's was cleared for good, for farms, mines or towns; the rest burned, was logged or can grow back.
Which country has more tree cover, Japan or South Korea?
South Korea does: its measured cities average 28.4% tree cover against 16.4%, a gap of 12.0 percentage points.
How many cities are the Japan and South Korea figures based on?
207 measured cities in Japan and 56 in South Korea. Every one was read the same way, so the two averages are directly comparable, but a country with more measured cities has the more settled figure.
Why are there two air quality averages for each country?
The first covers every measured city, using a ground station where one is close and a model estimate everywhere else. The second counts only cities with a current station reading, which is measured rather than estimated but covers fewer places. Airleaf's world rankings use the station figures only.
Does this cover the whole of Japan and South Korea?
The air and tree figures are not: they are the cities Airleaf has measured, each over the same 2 km radius, so treat them as a comparison of urban air and urban tree cover. The forest figures are: they count every forest in the country.
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