City report · England, United Kingdom
Bolton Air quality today
Air quality in Bolton currently reads AQI 39 (Good): Air quality is satisfactory for everyone.
Air quality right now
AQI 39
Good
- PM2.5, fine particles (µg/m³)
- 7.0
- tree cover
- 28.0%
- trees in this area
- 87.9K
- more trees needed
- 6.3K
Measured across a 1.2 mi (2 km) radius around Bolton, UK (4.9 sq mi), from a satellite image of Aug 8, 2026. Lower AQI is better: 0–50 is Good, above 300 is Hazardous.
Bolton · AQI 39 (Good)
Bolton's tree count comes to 87,877 trees across 4.8 sq mi (12.56 km²) of land, 2 points below the 30% tree-cover level considered healthy for this area, so roughly 6,277 more trees would close the gap.
Air quality detail
Air quality in Bolton today: AQI 39, Good
Main pollutant: PM2.5 · Observed Nov 11, 15:00 local time via OpenAQ and World Air Quality Index Project ground stations, US EPA index. Values in µg/m³.
Ground station · Salford Eccles, 8.0 mi (12.8 km) away · median of 2 stations
Health signal
Air quality is satisfactory for everyone.
PM2.5
7.0
PM10
10.2
NO₂
23.0
O₃
—
SO₂
—
CO
—
Data: OpenAQ · DEFRA, World Air Quality Index Project, UK-AIR, air quality information resource - Defra, UK, Great Air Manchester
- 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 Bolton's daily AQI at 61 on average, from 23 on Nov 4 to an hourly peak of 98 on Nov 8.
This is the US EPA AQI. How it differs from the UK's Daily Air Quality Index
Where Bolton stands: the most polluted cities in the world right now · the cleanest
Tree cover detail
Tree cover in Bolton: Below target
28.0% tree cover against a 30% healthy-neighborhood target, across 4.8 sq mi (12.56 km²) of land.
Trees in this area
87,877
Target trees
94,154
More trees needed
6,277
CO₂ if planted / yr
138.1 t
Deforestation · 2001–2025
How much forest has Bolton lost?
Since 2001, the area within 10 km of Bolton has lost about 156 hectares of forest (about 220 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 18 hectares (12%) was deforestation: forest cleared for good for farms, mines or towns.
2018: satellite photo from June 2018 of a 5 × 5 km area about 6 km north of the city center.
- Forest lost since 2001
- 156 haabout 220 football pitches
- Share of its forest
- 4%of what there was in 2000
- Cleared for good
- 18 hadeforestation: turned into farms, mines or towns
The worst year was 2005, when about 24 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 | 1 ha | 2 ha | 3 ha |
| 2002 | under 1 ha | 5 ha | 5 ha |
| 2003 | under 1 ha | under 1 ha | under 1 ha |
| 2004 | under 1 ha | 1 ha | 2 ha |
| 2005 | 6 ha | 18 ha | 24 ha |
| 2006 | 1 ha | 5 ha | 7 ha |
| 2007 | 1 ha | 6 ha | 7 ha |
| 2008 | 1 ha | 13 ha | 14 ha |
| 2009 | 4 ha | 6 ha | 9 ha |
| 2010 | 4 ha | 16 ha | 20 ha |
| 2011 | under 1 ha | under 1 ha | under 1 ha |
| 2012 | under 1 ha | 3 ha | 3 ha |
| 2013 | under 1 ha | under 1 ha | under 1 ha |
| 2014 | under 1 ha | under 1 ha | under 1 ha |
| 2015 | under 1 ha | under 1 ha | under 1 ha |
| 2016 | under 1 ha | under 1 ha | under 1 ha |
| 2017 | under 1 ha | 14 ha | 14 ha |
| 2018 | under 1 ha | 4 ha | 4 ha |
| 2019 | under 1 ha | 13 ha | 13 ha |
| 2020 | under 1 ha | 7 ha | 7 ha |
| 2021 | under 1 ha | 15 ha | 15 ha |
| 2022 | under 1 ha | 3 ha | 3 ha |
| 2023 | under 1 ha | 2 ha | 2 ha |
| 2024 | under 1 ha | 1 ha | 1 ha |
| 2025 | under 1 ha | 2 ha | 2 ha |
What is causing deforestation around Bolton?
- Loggingcan grow back76% · 118 ha
- Farms, pasture and plantationscleared for good8.4% · 13 ha
- Towns and roadscleared for good3.3% · 5 ha
Also: wildfires, 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
- 2,820 ha
- Forest in 2020
- 3,070 ha
- Overall change
- +251 hamore forest than in 2000
Comparing satellite maps from 2000 and 2020, the forest around Bolton grew from about 2,820 hectares to 3,070 hectares, a net gain of about 251 hectares (+8.9%). New forest grew on about 407 hectares, while 155 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 Bolton
Same 2 km radius, same index — so they compare directly.
- Wigan14.2 km
United Kingdom
- Tree cover
- 31%
- Air quality
- 25
- Manchester17.0 km
United Kingdom
- Tree cover
- 13%
- Air quality
- 53
- Blackburn18.8 km
United Kingdom
- Tree cover
- 29%
- Air quality
- 64
- Oldham21.3 km
United Kingdom
- Tree cover
- 23%
- Air quality
- 53
- Warrington23.3 km
United Kingdom
- Tree cover
- 25%
- Air quality
- 25
- St Helens24.8 km
United Kingdom
- Tree cover
- 31%
- Air quality
- 25
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Frequently asked
Questions about Bolton
What is the air quality (AQI) in Bolton right now?
The latest reading for Bolton shows an AQI of 39 (Good), measured Nov 11, 15:00 local time by 2 ground monitoring stations via OpenAQ (the median of their readings; the nearest is Salford Eccles, 8.0 mi (12.8 km) away). The main pollutant is PM2.5. Air quality is satisfactory for everyone.
Is it safe to exercise outside in Bolton 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 Bolton been like this week?
Over the last 7 days, the CAMS air-quality model put Bolton's daily AQI at 61 on average, from 23 on Nov 4 to an hourly peak of 98 on Nov 8. No day averaged above 100, the level where the air turns unhealthy for sensitive groups.
Is Bolton's AQI the same as the UK's Daily Air Quality Index?
No. Airleaf shows the US EPA Air Quality Index (AQI), the scale used by IQAir and most air-quality apps. The UK's Daily Air Quality Index (DAQI), published by Defra, runs from 1 to 10: 1–3 low, 4–6 moderate, 7–9 high and 10 very high. It is a different scale altogether, so a US AQI figure can't be read on it directly; both, though, are built from the same main pollutants, with fine particles (PM2.5) usually the one that decides the reading.
How much forest has the area around Bolton lost since 2001?
Since 2001, the area within 10 km of Bolton has lost about 156 hectares of forest (about 220 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 18 hectares (12%) was deforestation: forest cleared for good for farms, mines or towns. Comparing satellite maps from 2000 and 2020, the forest around Bolton grew from about 2,820 hectares to 3,070 hectares, a net gain of about 251 hectares (+8.9%). New forest grew on about 407 hectares, while 155 hectares were lost.
What is the tree count in Bolton?
Bolton has an estimated 87,877 trees across the 4.8 sq mi (12.56 km²) of land measured — 28.0% tree cover, 2 percentage points short of the 30% tree-cover target set for this area.
How many more trees does Bolton need?
Bolton needs roughly 6,277 more trees to close a 2-point shortfall against its 30% tree-cover target — about 138.1 t of extra CO₂ absorbed per year once grown.
How are Bolton's air quality and tree cover measured?
Air quality is measured by ground monitoring stations near Bolton, 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 1.2 mi (2 km) radius around Bolton; the tree count is an estimate derived from that cover.
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