Air quality comparison · France, 276 km apart
Lyon vs Marseille Air quality index (AQI) today
Lyon has cleaner air than Marseille right now: AQI 28 (Good) against 55 (Moderate).
That puts them in different EPA bands, so the health advice differs today. But over the past 6 days, on modeled daily averages, Marseille averaged AQI 30 against 59, and it was the cleaner of the two on 6 of those days. Marseille has lost more forest since 2001. Lyon has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Lyon28Marseille55
Head to head
Lyon vs Marseille at a glance
Lyon is ahead on 5 of 6 measures, and Marseille on 1. The better figure in each row is marked.
| Lyon | Marseille | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 28 (better) | 55 |
| PM2.5Fine particles, µg/m³. | 5 (better) | 11.3 |
| Past week's averageUS AQI, 6 days. | 59 | 30 (better) |
| Forest lost since 2001Within 10 km of the center. | 37 ha (better) | 347 ha |
| Tree coverWithin 2 km of the center. | 12.4% (better) | 9.4% |
| Trees still neededTo reach a healthy canopy. | 52.3K (better) | 61.1K |
Air quality today
What is the air like in Lyon and Marseille right now?
Lyon has cleaner air than Marseille right now: AQI 28 (Good) against 55 (Moderate). PM2.5 is setting the index in both.
Both readings come from nearby ground stations.
LyonMarseille
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).
The past week
Which had cleaner air over the past 6 days?
But over the past 6 days, on modeled daily averages, Marseille averaged AQI 30 against 59, and it was the cleaner of the two on 6 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
- Lyon0Marseille6
- Average AQI
- Lyon59Marseille30
- Worst day, AQI
- Lyon79Marseille47
The daily numbers (6 days)
| Day | Lyon | Marseille |
|---|---|---|
| Nov 5 | 79 | 21 |
| Nov 6 | 75 | 25 |
| Nov 7 | 71 | 47 |
| Nov 8 | 65 | 30 |
| Nov 9 | 31 | 26 |
| Nov 10 | 31 | 29 |
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 Lyon and Marseille today?
Lyon (AQI 28, Good): Air quality is satisfactory for everyone.
Marseille (AQI 55, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Exercise outdoors
- Lyon
- A good day to be active outside.
- Marseille
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
- Lyon
- Open them to air the house.
- Marseille
- Fine to open; close them if you are sensitive to pollution.
Masks
- Lyon
- Not needed.
- Marseille
- Not needed for most people.
Air purifier
- Lyon
- Not needed.
- Marseille
- Worth running if you are sensitive.
Against everywhere else
How do Lyon and Marseille compare with the rest of the world?
Right now Lyon's air is cleaner than 81% of the 5,420 places Airleaf tracks, and Marseille's is cleaner than 54%. Within France, that is 74% and 16% of its 39 measured places.
Cleaner air than…
- Lyon
- Beats 81%
- Marseille
- Beats 54%
More tree cover than…
- Lyon
- Beats 27%
- Marseille
- Beats 20%
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, Lyon or Marseille?
Marseille has lost more: about 347 ha of forest within 10 km of its center from 2001 to 2025, against 37 ha around Lyon. 69 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: 2008, with 5 ha lost.
Worst year: 2009, with 192 ha lost.
| Lyon | Marseille | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 37 ha (better) | 347 ha |
| Share of its forestOf what it had in 2000. | 1.1% (better) | 25% |
| Cleared for goodTurned into farms, mines or towns. | 22 ha (better) | 69 ha |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (58%) | Wildfires (76%) |
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.
Lyon
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Marseille
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Lyon or Marseille?
Lyon has more tree cover: 12.4% of the land within 2 km of its center against 9.4% around Marseille, or about 36,852 trees against 27,877.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Lyon | Marseille | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 36.9K (better) | 27.9K |
| Trees still neededTo reach the target. Fewer is better. | 52.3K (better) | 61.1K |
| CO₂ absorbed each yearBy the trees already standing. | 811K kg (better) | 613K kg |
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
Lyon vs Marseille: your questions answered
Is Lyon cleaner than Marseille?
On air quality, yes, right now: Lyon reads AQI 28 against 55, a gap of 27 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. But over the past 6 days, on modeled daily averages, Marseille averaged AQI 30 against 59, and it was the cleaner of the two on 6 of those days.
Is it safe to exercise outdoors in Lyon and Marseille today?
In Lyon, at AQI 28: Air quality is satisfactory for everyone. In Marseille, at AQI 55: Unusually sensitive people should consider limiting long outdoor exertion.
Which has lost more forest, Lyon or Marseille?
Marseille has lost more: about 347 ha of forest within 10 km of its center from 2001 to 2025, against 37 ha around Lyon. 69 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Lyon or Marseille?
Lyon has more tree cover: 12.4% of the land within 2 km of its center against 9.4% around Marseille, or about 36,852 trees against 27,877. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Lyon and Marseille need?
Lyon needs about 52,306 more to reach its canopy target of 30%, and Marseille about 61,093 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Lyon and Marseille 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. Both readings come from nearby ground stations. Nothing is adjusted for population, city limits or climate.
How often does the Lyon vs Marseille 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 15, 2026), and the forest figures are published yearly.
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