Air quality comparison · North Korea, 171 km apart
Kaesŏng vs Sunch’ŏn Air quality index (AQI) today
Kaesŏng has cleaner air than Sunch’ŏn right now: AQI 81 (Moderate) against 156 (Unhealthy).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Kaesŏng averaged AQI 48 against 69, and it was the cleaner of the two on 7 of those days. Kaesŏng has lost more forest since 2001. Sunch’ŏn has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Kaesŏng81Sunch’ŏn156
Head to head
Kaesŏng vs Sunch’ŏn at a glance
Kaesŏng and Sunch’ŏn are level, each ahead on 3 of 6 measures. The better figure in each row is marked.
| Kaesŏng | Sunch’ŏn | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 81 (better) | 156 |
| PM2.5Fine particles, µg/m³. | 25 (better) | 69.4 |
| Past week's averageUS AQI, 7 days. | 48 (better) | 69 |
| Forest lost since 2001Within 10 km of the center. | 6 ha | 4 ha (better) |
| Tree coverWithin 2 km of the center. | 10.0% | 18.6% (better) |
| Trees still neededTo reach a healthy canopy. | 62.8K | 59.6K (better) |
Air quality today
What is the air like in Kaesŏng and Sunch’ŏn right now?
Kaesŏng has cleaner air than Sunch’ŏn right now: AQI 81 (Moderate) against 156 (Unhealthy). PM2.5 is setting the index in both.
Kaesŏng's PM2.5 is about 1.7× the WHO's 24-hour guideline of 15 µg/m³. Sunch’ŏn's PM2.5 is about 4.6× the WHO's 24-hour guideline of 15 µg/m³.
Kaesŏng is read from a nearby ground station and Sunch’ŏn is a model estimate, so the two are not quite like for like.
KaesŏngSunch’ŏn
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).
Kaesŏng: Ground station · 파주, 17.1 km away · median of 2 stations. Data: OpenAQ · Korea Air Ministry of Environment, Korea Environment Corporation · AirKorea.
Sunch’ŏn: Estimate · model corrected with 2 station cities within 165 km, e.g. Sinuiju and Dandong. Data: Open-Meteo / CAMS, corrected with 2 ground-station cities within 165 km, US EPA index.
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Kaesŏng averaged AQI 48 against 69, and it was the cleaner of the two on 7 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
- Kaesŏng7Sunch’ŏn0
- Average AQI
- Kaesŏng48Sunch’ŏn69
- Worst day, AQI
- Kaesŏng83Sunch’ŏn109
The daily numbers (7 days)
| Day | Kaesŏng | Sunch’ŏn |
|---|---|---|
| Nov 5 | 79 | 109 |
| Nov 6 | 46 | 50 |
| Nov 7 | 38 | 40 |
| Nov 8 | 21 | 42 |
| Nov 9 | 27 | 58 |
| Nov 10 | 45 | 80 |
| Nov 11 | 83 | 105 |
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 Kaesŏng and Sunch’ŏn today?
Kaesŏng (AQI 81, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Sunch’ŏn (AQI 156, Unhealthy): Everyone should limit long outdoor exertion; sensitive groups more so.
Exercise outdoors
- Kaesŏng
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
- Sunch’ŏn
- Everyone should cut down long or hard exercise; sensitive groups should avoid it.
Windows
- Kaesŏng
- Fine to open; close them if you are sensitive to pollution.
- Sunch’ŏn
- Keep them closed.
Masks
- Kaesŏng
- Not needed for most people.
- Sunch’ŏn
- Wear an N95 outdoors.
Air purifier
- Kaesŏng
- Worth running if you are sensitive.
- Sunch’ŏn
- Run one.
Against everywhere else
How do Kaesŏng and Sunch’ŏn compare with the rest of the world?
Right now Kaesŏng's air is cleaner than 30% of the 5,420 places Airleaf tracks, and Sunch’ŏn's is cleaner than 9%. Within North Korea, that is 36% and 7% of its 29 measured places.
Cleaner air than…
- Kaesŏng
- Beats 30%
- Sunch’ŏn
- Beats 9%
More tree cover than…
- Kaesŏng
- Beats 21%
- Sunch’ŏn
- Beats 43%
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, Kaesŏng or Sunch’ŏn?
Kaesŏng has lost more: about 6 ha of forest within 10 km of its center from 2001 to 2025, against 4 ha around Sunch’ŏn. under 1 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: 2011, with 1 ha lost.
Worst year: 2002, with 1 ha lost.
| Kaesŏng | Sunch’ŏn | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 6 ha | 4 ha (better) |
| Share of its forestOf what it had in 2000. | under 1% (better) | 1.1% |
| Cleared for goodTurned into farms, mines or towns. | under 1 ha (better) | under 1 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Logging (78%) | Logging (53%) |
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.
Kaesŏng
2017: satellite photo from September 2017 of a 5 × 5 km area in the city center.
Sunch’ŏn
2017: satellite photo from June 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Kaesŏng or Sunch’ŏn?
Sunch’ŏn has more tree cover: 18.6% of the land within 2 km of its center against 10.0% around Kaesŏng, or about 51,772 trees against 31,416.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Kaesŏng | Sunch’ŏn | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 31.4K | 51.8K (better) |
| Trees still neededTo reach the target. Fewer is better. | 62.8K | 59.6K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 691K kg | 1.1M kg (better) |
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
Kaesŏng vs Sunch’ŏn: your questions answered
Is Kaesŏng cleaner than Sunch’ŏn?
On air quality, yes, right now: Kaesŏng reads AQI 81 against 156, a gap of 75 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. Over the past 7 days, on modeled daily averages, Kaesŏng averaged AQI 48 against 69, and it was the cleaner of the two on 7 of those days.
Is it safe to exercise outdoors in Kaesŏng and Sunch’ŏn today?
In Kaesŏng, at AQI 81: Unusually sensitive people should consider limiting long outdoor exertion. In Sunch’ŏn, at AQI 156: Everyone should limit long outdoor exertion; sensitive groups more so.
Which has lost more forest, Kaesŏng or Sunch’ŏn?
Kaesŏng has lost more: about 6 ha of forest within 10 km of its center from 2001 to 2025, against 4 ha around Sunch’ŏn. under 1 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Kaesŏng or Sunch’ŏn?
Sunch’ŏn has more tree cover: 18.6% of the land within 2 km of its center against 10.0% around Kaesŏng, or about 51,772 trees against 31,416. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Kaesŏng and Sunch’ŏn need?
Kaesŏng needs about 62,832 more to reach its canopy target of 30%, and Sunch’ŏn about 59,566 to reach 40%. The target starts at 30% of the land and rises where air quality is poor.
Are Kaesŏng and Sunch’ŏn 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. Kaesŏng is read from a nearby ground station and Sunch’ŏn is a model estimate, so the two are not quite like for like. Nothing is adjusted for population, city limits or climate.
How often does the Kaesŏng vs Sunch’ŏn 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 18, 2026), and the forest figures are published yearly.
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