City report · Brittany, France
Rennes Air quality today
Air quality in Rennes currently reads AQI 40 (Good): Air quality is satisfactory for everyone.
Air quality right now
AQI 40
Good
- PM2.5, fine particles (µg/m³)
- 7.2
- tree cover
- 27.8%
- trees in this area
- 87.2K
- more trees needed
- 6.9K
Measured across a 2 km radius around Thabor - Saint Hélier, Rennes, France (12.57 km²), from a satellite image of Sep 22, 2026. Lower AQI is better: 0–50 is Good, above 300 is Hazardous.
Rennes · AQI 40 (Good)
Rennes's tree count comes to 87,249 trees across 12.56 km² of land, 2 points below the 30% tree-cover level considered healthy for this area, so roughly 6,905 more trees would close the gap.
Air quality detail
Air quality in Rennes today: AQI 40, Good
Main pollutant: PM2.5 · Observed Nov 11, 15:00 local time via OpenAQ ground stations, US EPA index. Values in µg/m³.
Ground station · Rennes Laennec, 700 m away · median of 3 stations
Health signal
Air quality is satisfactory for everyone.
PM2.5
7.2
PM10
13.1
NO₂
10.4
O₃
42.6
SO₂
—
CO
—
Data: OpenAQ · EEA
- 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 Rennes's daily AQI at 62 on average, from 45 on Nov 3 to an hourly peak of 80 on Nov 6.
Where Rennes stands: the most polluted cities in the world right now · the cleanest
Tree cover detail
Tree cover in Rennes: Below target
27.8% tree cover against a 30% healthy-neighborhood target, across 12.56 km² of land.
Trees in this area
87,249
Target trees
94,154
More trees needed
6,905
CO₂ if planted / yr
151.9 t
Deforestation · 2001–2025
How much forest has Rennes lost?
Since 2001, the area within 10 km of Rennes has lost about 51 hectares of forest (about 72 football pitches): 1.9% of the forest it had in 2000. Most of it was lost to logging, so much of it can grow back. About 4 hectares (8.2%) was deforestation: forest cleared for good for farms, mines or towns.
2017: satellite photo from July 2017 of a 5 × 5 km area in the city center.
- Forest lost since 2001
- 51 haabout 72 football pitches
- Share of its forest
- 1.9%of what there was in 2000
- Cleared for good
- 4 hadeforestation: turned into farms, mines or towns
The worst year was 2010, when about 10 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 | under 1 ha | 3 ha | 3 ha |
| 2002 | under 1 ha | under 1 ha | under 1 ha |
| 2003 | under 1 ha | under 1 ha | under 1 ha |
| 2004 | under 1 ha | 5 ha | 5 ha |
| 2005 | under 1 ha | under 1 ha | under 1 ha |
| 2006 | under 1 ha | 2 ha | 2 ha |
| 2007 | under 1 ha | under 1 ha | under 1 ha |
| 2008 | under 1 ha | 2 ha | 2 ha |
| 2009 | under 1 ha | 4 ha | 4 ha |
| 2010 | under 1 ha | 10 ha | 10 ha |
| 2011 | 1 ha | under 1 ha | 2 ha |
| 2012 | under 1 ha | 4 ha | 4 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 | 2 ha | 2 ha |
| 2016 | under 1 ha | under 1 ha | 2 ha |
| 2017 | under 1 ha | 3 ha | 3 ha |
| 2018 | under 1 ha | under 1 ha | under 1 ha |
| 2019 | under 1 ha | 2 ha | 2 ha |
| 2020 | under 1 ha | 2 ha | 2 ha |
| 2021 | under 1 ha | under 1 ha | under 1 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 | under 1 ha | under 1 ha |
What is causing deforestation around Rennes?
- Loggingcan grow back66% · 34 ha
- Towns and roadscleared for good7% · 4 ha
- Farms, pasture and plantationscleared for good1.2% · under 1 ha
Also: 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
- 4,650 ha
- Forest in 2020
- 4,970 ha
- Overall change
- +320 hamore forest than in 2000
Comparing satellite maps from 2000 and 2020, the forest around Rennes grew from about 4,650 hectares to 4,970 hectares, a net gain of about 320 hectares (+6.9%). New forest grew on about 443 hectares, while 123 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 Rennes
Same 2 km radius, same index — so they compare directly.
- Angers109.9 km
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- Tree cover
- 23%
- Air quality
- 53
- Saint Helier123.9 km
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- Tree cover
- 26%
- Air quality
- 36
- Le Mans140.0 km
France
- Tree cover
- 28%
- Air quality
- 52
- Caen153.7 km
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- Tree cover
- 24%
- Air quality
- 34
- Saint Peter Port162.7 km
Guernsey
- Tree cover
- 36%
- Air quality
- 24
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Frequently asked
Questions about Rennes
What is the air quality (AQI) in Rennes right now?
The latest reading for Rennes shows an AQI of 40 (Good), measured Nov 11, 15:00 local time by 3 ground monitoring stations via OpenAQ (the median of their readings; the nearest is Rennes Laennec, 700 m away). The main pollutant is PM2.5. Air quality is satisfactory for everyone.
Is it safe to exercise outside in Rennes today?
At AQI 40 (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 Rennes been like this week?
Over the last 7 days, the CAMS air-quality model put Rennes's daily AQI at 62 on average, from 45 on Nov 3 to an hourly peak of 80 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 Rennes lost since 2001?
Since 2001, the area within 10 km of Rennes has lost about 51 hectares of forest (about 72 football pitches): 1.9% of the forest it had in 2000. Most of it was lost to logging, so much of it can grow back. About 4 hectares (8.2%) was deforestation: forest cleared for good for farms, mines or towns. Comparing satellite maps from 2000 and 2020, the forest around Rennes grew from about 4,650 hectares to 4,970 hectares, a net gain of about 320 hectares (+6.9%). New forest grew on about 443 hectares, while 123 hectares were lost.
What is the tree count in Rennes?
Rennes has an estimated 87,249 trees across the 12.56 km² of land measured — 27.8% tree cover, 2 percentage points short of the 30% tree-cover target set for this area.
How many more trees does Rennes need?
Rennes needs roughly 6,905 more trees to close a 2-point shortfall against its 30% tree-cover target — about 151.9 t of extra CO₂ absorbed per year once grown.
How are Rennes's air quality and tree cover measured?
Air quality is measured by ground monitoring stations near Thabor - Saint Hélier, 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 Thabor - Saint Hélier; the tree count is an estimate derived from that cover.
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