Air quality comparison · France, 112 km apart
Marne La Vallée vs Reims Air quality index (AQI) today
Reims has cleaner air than Marne La Vallée right now: AQI 29 (Good) against 36 (Good).
Both sit in the same EPA band, so the health advice is the same for each today. Over the past 6 days, on modeled daily averages, Reims averaged AQI 75 against 78, and it was the cleaner of the two on 3 of those days. Marne La Vallée has lost more forest since 2001. Marne La Vallée has more tree cover.
France
AQI 36
Good
Cleaner right now
- PM2.5
- 6.4 µg/m³
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 17:00 local
France
AQI 29
Good
Cleaner right now
- PM2.5
- 5.3 µg/m³
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 17:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Marne La Vallée36Reims29
Head to head
Marne La Vallée vs Reims at a glance
Reims is ahead on 4 of 6 measures, and Marne La Vallée on 2. The better figure in each row is marked.
| Marne La Vallée | Reims | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 36 | 29 (better) |
| PM2.5Fine particles, µg/m³. | 6.4 | 5.3 (better) |
| Past week's averageUS AQI, 6 days. | 78 | 75 (better) |
| Forest lost since 2001Within 10 km of the center. | 336 ha | 223 ha (better) |
| Tree coverWithin 2 km of the center. | 38.8% (better) | 16.9% |
| Trees still neededTo reach a healthy canopy. | 0 (better) | 41.1K |
Air quality today
What is the air like in Marne La Vallée and Reims right now?
Reims has cleaner air than Marne La Vallée right now: AQI 29 (Good) against 36 (Good). PM2.5 is setting the index in both.
Both readings come from nearby ground stations.
Marne La ValléeReims
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?
Over the past 6 days, on modeled daily averages, Reims averaged AQI 75 against 78, and it was the cleaner of the two on 3 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
- Marne La Vallée3Reims3
- Average AQI
- Marne La Vallée78Reims75
- Worst day, AQI
- Marne La Vallée103Reims86
The daily numbers (6 days)
| Day | Marne La Vallée | Reims |
|---|---|---|
| Nov 5 | 66 | 60 |
| Nov 6 | 89 | 83 |
| Nov 7 | 103 | 86 |
| Nov 8 | 74 | 75 |
| Nov 9 | 68 | 74 |
| Nov 10 | 65 | 71 |
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 Marne La Vallée and Reims today?
Air quality is satisfactory for everyone. Both are in the same EPA band today (Good), so the advice is the same.
Exercise outdoors
A good day to be active outside.
Windows
Open them to air the house.
Masks
Not needed.
Air purifier
Not needed.
Against everywhere else
How do Marne La Vallée and Reims compare with the rest of the world?
Right now Marne La Vallée's air is cleaner than 73% of the 5,420 places Airleaf tracks, and Reims's is cleaner than 80%. Within France, that is 37% and 71% of its 39 measured places.
Cleaner air than…
- Marne La Vallée
- Beats 73%
- Reims
- Beats 80%
More tree cover than…
- Marne La Vallée
- Beats 82%
- Reims
- Beats 39%
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, Marne La Vallée or Reims?
Marne La Vallée has lost more: about 336 ha of forest within 10 km of its center from 2001 to 2025, against 223 ha around Reims. 100 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: 2023, with 65 ha lost.
Worst year: 2004, with 46 ha lost.
| Marne La Vallée | Reims | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 336 ha | 223 ha (better) |
| Share of its forestOf what it had in 2000. | 3.4% (better) | 8.1% |
| Cleared for goodTurned into farms, mines or towns. | 100 ha | 52 ha (better) |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Logging (65%) | Logging (72%) |
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.
Marne La Vallée
2017: satellite photo from August 2017 of a 5 × 5 km area about 6 km southeast of the city center.
Reims
2017: satellite photo from August 2017 of a 5 × 5 km area about 7 km west of the city center.
Trees
Which has more trees, Marne La Vallée or Reims?
Marne La Vallée has more tree cover: 38.8% of the land within 2 km of its center against 16.9% around Reims, or about 120,187 trees against 53,040.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Marne La Vallée | Reims | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 120K (better) | 53.0K |
| Trees still neededTo reach the target. Fewer is better. | 0 (better) | 41.1K |
| CO₂ absorbed each yearBy the trees already standing. | 2.6M kg (better) | 1.2M 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
Marne La Vallée vs Reims: your questions answered
Is Reims cleaner than Marne La Vallée?
On air quality, yes, right now: Reims reads AQI 29 against 36, a gap of 7 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. Over the past 6 days, on modeled daily averages, Reims averaged AQI 75 against 78, and it was the cleaner of the two on 3 of those days.
Is it safe to exercise outdoors in Marne La Vallée and Reims today?
The advice is the same for both today. Air quality is satisfactory for everyone. Marne La Vallée reads AQI 36 and Reims reads AQI 29.
Which has lost more forest, Marne La Vallée or Reims?
Marne La Vallée has lost more: about 336 ha of forest within 10 km of its center from 2001 to 2025, against 223 ha around Reims. 100 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Marne La Vallée or Reims?
Marne La Vallée has more tree cover: 38.8% of the land within 2 km of its center against 16.9% around Reims, or about 120,187 trees against 53,040. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Marne La Vallée and Reims need?
Marne La Vallée needs about 0 more to reach its canopy target of 30%, and Reims about 41,114 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Marne La Vallée and Reims 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 Marne La Vallée vs Reims 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 1, 2026 and Sep 26, 2026), and the forest figures are published yearly.
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