City report · Henan, China
Sanmenxia Air quality today
Air quality in Sanmenxia currently reads AQI 161 (Unhealthy): Everyone should limit long outdoor exertion; sensitive groups more so.
AQI 161
Air quality right now
Unhealthy
- PM2.5, fine particles (µg/m³)
- 69.1
- tree cover
- 20.4%
- trees in this area
- 64.0K
- more trees needed
- 61.5K
Measured across a 2 km radius around Hubin District, Sanmenxia, Henan, China (12.57 km²), from a satellite image of Sep 6, 2026. Lower AQI is better: 0–50 is Good, above 300 is Hazardous.
Sanmenxia · AQI 161 (Unhealthy)
Sanmenxia's tree count comes to 63,960 trees across 12.54 km² of land, 20 points below the 40% tree-cover level considered healthy for this area, so roughly 61,452 more trees would close the gap.
Air quality detail
Air quality in Sanmenxia today: AQI 161, Unhealthy
Main pollutant: PM2.5 · Observed Nov 11, 23:00 local time via World Air Quality Index Project ground stations, US EPA index. Values in µg/m³.
Ground station · City government, Sanmenxia (三门峡市政府), 400 m away · median of 3 stations
Health signal
Everyone should limit long outdoor exertion; sensitive groups more so.
PM2.5
69.1
PM10
105.5
NO₂
—
O₃
—
SO₂
—
CO
—
Data: World Air Quality Index Project, Henan Environmental Protection Agency (河南环保 > 网站首页), China National Urban air quality real-time publishing platform (全国城市空气质量实时发布平台)
- Outdoor exercise
- Everyone should cut down long or hard exercise; sensitive groups should avoid it
- Windows
- Keep them closed
- Mask
- Wear an N95 outdoors
- Air purifier
- Run one
Over the last 7 days, the CAMS air-quality model put Sanmenxia's daily AQI at 104 on average, from 83 on Nov 9 to an hourly peak of 152 on Nov 6.
Where Sanmenxia stands: the most polluted cities in the world right now · the cleanest
Tree cover detail
Tree cover in Sanmenxia: Critically low
20.4% tree cover against a 40% healthy-neighborhood target, across 12.54 km² of land.
Trees in this area
63,960
Target trees
125,412
More trees needed
61,452
CO₂ if planted / yr
1,352 t
Deforestation · 2001–2025
How much forest has Sanmenxia lost?
There was almost no forest around Sanmenxia in 2000, so there has been almost nothing to lose since. Only fairly dense woodland counts as forest in these maps, so scattered street and garden trees don't show up here.
2017: satellite photo from July 2017 of a 5 × 5 km area in the city center.
Forest gained and lost, 2000–2020
- Forest in 2000
- 1,330 ha
- Forest in 2020
- 1,780 ha
- Overall change
- +455 hamore forest than in 2000
Comparing satellite maps from 2000 and 2020, the forest around Sanmenxia grew from about 1,330 hectares to 1,780 hectares, a net gain of about 455 hectares (+34%). New forest grew on about 498 hectares, while 43 hectares were lost.
These 2000 and 2020 maps, from the University of Maryland, count any land with trees taller than 5 m as forest, including plantations and orchards. Forest that was cut or burned and had grown back by 2020 counts in both years, so the loss here is smaller than the yearly figures.
These figures cover everything within 10 km of the city center, a wider area than the report above, because forest is usually lost at a city's edges.
Source: Hansen/UMD/Google/USGS/NASA, Global Forest Change (GFC-2025-v1.13); causes: WRI/Google DeepMind drivers of forest loss; both CC BY 4.0, summed by Airleaf for each area. Forest gained and lost 2000–2020: Potapov et al. 2022, UMD GLAD Global Land Cover and Land Use Change, CC BY 4.0. Images: contains modified Copernicus Sentinel data. How it's measured
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Frequently asked
Questions about Sanmenxia
What is the air quality (AQI) in Sanmenxia right now?
The latest reading for Sanmenxia shows an AQI of 161 (Unhealthy), measured Nov 11, 23:00 local time by 3 ground monitoring stations via OpenAQ (the median of their readings; the nearest is City government, Sanmenxia (三门峡市政府), 400 m away). The main pollutant is PM2.5. Everyone should limit long outdoor exertion; sensitive groups more so.
Is it safe to exercise outside in Sanmenxia today?
At AQI 161 (Unhealthy): everyone should cut down long or hard exercise; sensitive groups should avoid it. Windows: keep them closed. Masks: wear an N95 outdoors. The reading changes through the day, so check again before a long run or ride.
What has the air quality in Sanmenxia been like this week?
Over the last 7 days, the CAMS air-quality model put Sanmenxia's daily AQI at 104 on average, from 83 on Nov 9 to an hourly peak of 152 on Nov 6. On 4 of those days the average was above 100, unhealthy for sensitive groups.
How much forest has the area around Sanmenxia lost since 2001?
There was almost no forest around Sanmenxia in 2000, so there has been almost nothing to lose since. Only fairly dense woodland counts as forest in these maps, so scattered street and garden trees don't show up here. Comparing satellite maps from 2000 and 2020, the forest around Sanmenxia grew from about 1,330 hectares to 1,780 hectares, a net gain of about 455 hectares (+34%). New forest grew on about 498 hectares, while 43 hectares were lost.
What is the tree count in Sanmenxia?
Sanmenxia has an estimated 63,960 trees across the 12.54 km² of land measured — 20.4% tree cover, 20 percentage points short of the 40% tree-cover target set for this area.
How many more trees does Sanmenxia need?
Sanmenxia needs roughly 61,452 more trees to close a 20-point shortfall against its 40% tree-cover target — about 1,352 t of extra CO₂ absorbed per year once grown.
How are Sanmenxia's air quality and tree cover measured?
Air quality is measured by ground monitoring stations near Hubin District, via OpenAQ; the 7-day trend is the Open-Meteo / CAMS model's estimate. Tree cover is measured from Sentinel-2 L2A (ESA Copernicus) via Earth Search satellite imagery at 10 m detail across a 2 km radius around Hubin District; the tree count is an estimate derived from that cover.
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