City report · Nagasaki, Japan
Isahaya Air quality today
Air quality in Isahaya currently reads AQI 39 (Good): Air quality is satisfactory for everyone.
AQI 39
Air quality right now
Good
- PM2.5, fine particles (µg/m³)
- 7.0
- tree cover
- 31.3%
- trees in this area
- 98.3K
- more trees needed
- 0
Measured across a 2 km radius around 29 Uzumachi, Isahaya, Nagasaki 854-0061, Japan (12.57 km²), from a satellite image of Sep 25, 2026. Lower AQI is better: 0–50 is Good, above 300 is Hazardous.
Isahaya · AQI 39 (Good)
Isahaya's tree count comes to 98,332 trees across 12.57 km², already at or above the 30% tree-cover level considered healthy for this area.
Air quality detail
Air quality in Isahaya today: AQI 39, Good
Main pollutant: PM2.5 · Observed Nov 12, 01:00 local time via OpenAQ ground stations, US EPA index. Values in µg/m³.
Ground station · 諌早市馬渡町13, 2.5 km away
Health signal
Air quality is satisfactory for everyone.
PM2.5
7.0
PM10
—
NO₂
—
O₃
—
SO₂
0.0
CO
—
Data: OpenAQ · Ministry of the Environment Air Pollutant Wide Area Monitoring System
- Outdoor exercise
- A good day to be active outside
- Windows
- Open them to air the house
- Mask
- Not needed
- Air purifier
- Not needed
Over the last 7 days, the CAMS air-quality model put Isahaya's daily AQI at 40 on average, from 19 on Nov 10 to an hourly peak of 77 on Nov 6.
Where Isahaya stands: the most polluted cities in the world right now · the cleanest
Tree cover detail
Tree cover in Isahaya: Healthy tree cover
31.3% tree cover against a 30% healthy-neighborhood target, across 12.57 km².
Trees in this area
98,332
Target trees
98,332
More trees needed
0
CO₂ if planted / yr
0 kg
Deforestation · 2001–2025
How much forest has Isahaya lost?
Since 2001, the area within 10 km of Isahaya has lost about 500 hectares of forest (about 700 football pitches): 4% of the forest it had in 2000. Most of it was lost to logging, so much of it can grow back. About 217 hectares (43%) was deforestation: forest cleared for good for farms, mines or towns.
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km north of the city center.
- Forest lost since 2001
- 500 haabout 700 football pitches
- Share of its forest
- 4%of what there was in 2000
- Cleared for good
- 217 hadeforestation: turned into farms, mines or towns
The worst year was 2016, when about 35 hectares of forest were lost.
Hectares of forest lost each year
Show the figures as a table
| Year | Cleared for good | Can grow back | Total |
|---|---|---|---|
| 2001 | 10 ha | 6 ha | 17 ha |
| 2002 | 4 ha | 5 ha | 9 ha |
| 2003 | 3 ha | 6 ha | 10 ha |
| 2004 | 11 ha | 13 ha | 24 ha |
| 2005 | 12 ha | 7 ha | 19 ha |
| 2006 | 10 ha | 11 ha | 21 ha |
| 2007 | 5 ha | 13 ha | 18 ha |
| 2008 | 8 ha | 5 ha | 14 ha |
| 2009 | 9 ha | 11 ha | 21 ha |
| 2010 | 9 ha | 15 ha | 25 ha |
| 2011 | 7 ha | 21 ha | 29 ha |
| 2012 | 12 ha | 19 ha | 31 ha |
| 2013 | 2 ha | 5 ha | 8 ha |
| 2014 | 2 ha | 7 ha | 9 ha |
| 2015 | 6 ha | 12 ha | 18 ha |
| 2016 | 16 ha | 20 ha | 35 ha |
| 2017 | 19 ha | 13 ha | 31 ha |
| 2018 | 5 ha | 20 ha | 25 ha |
| 2019 | 23 ha | 9 ha | 32 ha |
| 2020 | 6 ha | 10 ha | 15 ha |
| 2021 | 10 ha | 17 ha | 27 ha |
| 2022 | 10 ha | 10 ha | 20 ha |
| 2023 | 8 ha | 5 ha | 13 ha |
| 2024 | 3 ha | 10 ha | 13 ha |
| 2025 | 6 ha | 11 ha | 17 ha |
What is causing deforestation around Isahaya?
- Loggingcan grow back54% · 268 ha
- Towns and roadscleared for good42% · 208 ha
- Farms, pasture and plantationscleared for good1.2% · 6 ha
Also: mining and energy, unknown causes.
Causes for 2025 are estimates, based on what caused forest loss in the same places up to 2024.
Forest gained and lost, 2000–2020
- Forest in 2000
- 14,700 ha
- Forest in 2020
- 14,600 ha
- Overall change
- −75 haless forest than in 2000
Comparing satellite maps from 2000 and 2020, the forest around Isahaya stayed about the same size, at about 14,600 hectares: new forest grew on about 131 hectares, and about 206 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
In the same region
Measured cities near Isahaya
Same 2 km radius, same index — so they compare directly.
Build your own
Compare Isahaya with anywhere
This place
Isahaya
Use this data
Put Isahaya's numbers on your site
Free to embed. Updates itself as the measurement refreshes.
Frequently asked
Questions about Isahaya
What is the air quality (AQI) in Isahaya right now?
The latest reading for Isahaya shows an AQI of 39 (Good), measured Nov 12, 01:00 local time by the 諌早市馬渡町13 ground monitoring station, 2.5 km away, via OpenAQ. The main pollutant is PM2.5. Air quality is satisfactory for everyone.
Is it safe to exercise outside in Isahaya today?
At AQI 39 (Good): a good day to be active outside. Windows: open them to air the house. Masks: not needed. The reading changes through the day, so check again before a long run or ride.
What has the air quality in Isahaya been like this week?
Over the last 7 days, the CAMS air-quality model put Isahaya's daily AQI at 40 on average, from 19 on Nov 10 to an hourly peak of 77 on Nov 6. No day averaged above 100, the level where the air turns unhealthy for sensitive groups.
How much forest has the area around Isahaya lost since 2001?
Since 2001, the area within 10 km of Isahaya has lost about 500 hectares of forest (about 700 football pitches): 4% of the forest it had in 2000. Most of it was lost to logging, so much of it can grow back. About 217 hectares (43%) was deforestation: forest cleared for good for farms, mines or towns. Comparing satellite maps from 2000 and 2020, the forest around Isahaya stayed about the same size, at about 14,600 hectares: new forest grew on about 131 hectares, and about 206 hectares were lost.
What is the tree count in Isahaya?
Isahaya has an estimated 98,332 trees across the 12.57 km² measured — 31.3% tree cover, already past the 30% tree-cover target set for this area.
How many more trees does Isahaya need?
Isahaya has already reached its tree-cover target, so no additional trees are needed to close the gap.
How are Isahaya's air quality and tree cover measured?
Air quality is measured by ground monitoring stations near 29 Uzumachi, 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 29 Uzumachi; the tree count is an estimate derived from that cover.
See your own area
What does your neighborhood look like?
Pick any point and radius to get the same air-quality and tree-cover breakdown.
Check my address