Air quality comparison · French Guiana, 198 km apart
Cayenne vs Saint-Laurent-du-Maroni Air quality index (AQI) today
Cayenne has cleaner air than Saint-Laurent-du-Maroni right now: AQI 48 (Good) against 55 (Moderate).
That puts them in different EPA bands, so the health advice differs today. Over the past 7 days, on modeled daily averages, Cayenne averaged AQI 22 against 37, and it was the cleaner of the two on 7 of those days. Saint-Laurent-du-Maroni has lost more forest since 2001. Cayenne has more tree cover.
French Guiana
AQI 48
Good
Cleaner right now
- PM2.5
- 8.6 µg/m³
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 14:00 local
French Guiana
AQI 55
Moderate
Cleaner right now
- PM2.5
- 10 µg/m³
- Main pollutant
- PM2.5
- Source
- Model estimate
- Reading
- Nov 10, 20:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Cayenne48Saint-Laurent-du-Maroni55
Head to head
Cayenne vs Saint-Laurent-du-Maroni at a glance
Cayenne is ahead on 5 of 6 measures, and Saint-Laurent-du-Maroni on 0. The better figure in each row is marked.
| Cayenne | Saint-Laurent-du-Maroni | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 48 (better) | 55 |
| PM2.5Fine particles, µg/m³. | 8.6 (better) | 10 |
| Past week's averageUS AQI, 7 days. | 22 (better) | 37 |
| Forest lost since 2001Within 10 km of the center. | 1,870 ha (better) | 4,320 ha |
| Tree coverWithin 2 km of the center. | 48.5% (better) | 42.4% |
| Trees still neededTo reach a healthy canopy. | 0 | 0 |
Air quality today
What is the air like in Cayenne and Saint-Laurent-du-Maroni right now?
Cayenne has cleaner air than Saint-Laurent-du-Maroni right now: AQI 48 (Good) against 55 (Moderate). PM2.5 is setting the index in both.
Cayenne is read from a nearby ground station and Saint-Laurent-du-Maroni is a model estimate, so the two are not quite like for like.
CayenneSaint-Laurent-du-Maroni
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).
Cayenne: Ground station · Cayenne-Bouchon, 2.4 km away · median of 2 stations. Data: OpenAQ · EEA.
Saint-Laurent-du-Maroni: Estimate · model corrected with 2 station cities within 205 km, e.g. Kourou and Cayenne. Data: Open-Meteo / CAMS, corrected with 2 ground-station cities within 205 km, US EPA index.
The past week
Which had cleaner air over the past 7 days?
Over the past 7 days, on modeled daily averages, Cayenne averaged AQI 22 against 37, and it was the cleaner of the two on 7 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
- Cayenne7Saint-Laurent-du-Maroni0
- Average AQI
- Cayenne22Saint-Laurent-du-Maroni37
- Worst day, AQI
- Cayenne31Saint-Laurent-du-Maroni46
The daily numbers (7 days)
| Day | Cayenne | Saint-Laurent-du-Maroni |
|---|---|---|
| Nov 4 | 25 | 41 |
| Nov 5 | 24 | 42 |
| Nov 6 | 26 | 46 |
| Nov 7 | 31 | 43 |
| Nov 8 | 16 | 37 |
| Nov 9 | 15 | 24 |
| Nov 10 | 20 | 28 |
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 Cayenne and Saint-Laurent-du-Maroni today?
Cayenne (AQI 48, Good): Air quality is satisfactory for everyone.
Saint-Laurent-du-Maroni (AQI 55, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Exercise outdoors
- Cayenne
- A good day to be active outside.
- Saint-Laurent-du-Maroni
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
- Cayenne
- Open them to air the house.
- Saint-Laurent-du-Maroni
- Fine to open; close them if you are sensitive to pollution.
Masks
- Cayenne
- Not needed.
- Saint-Laurent-du-Maroni
- Not needed for most people.
Air purifier
- Cayenne
- Not needed.
- Saint-Laurent-du-Maroni
- Worth running if you are sensitive.
Against everywhere else
How do Cayenne and Saint-Laurent-du-Maroni compare with the rest of the world?
Right now Cayenne's air is cleaner than 63% of the 5,420 places Airleaf tracks, and Saint-Laurent-du-Maroni's is cleaner than 54%.
Cleaner air than…
- Cayenne
- Beats 63%
- Saint-Laurent-du-Maroni
- Beats 54%
More tree cover than…
- Cayenne
- Beats 91%
- Saint-Laurent-du-Maroni
- Beats 86%
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, Cayenne or Saint-Laurent-du-Maroni?
Saint-Laurent-du-Maroni has lost more: about 4,320 ha of forest within 10 km of its center from 2001 to 2025, against 1,870 ha around Cayenne. 3,950 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: 2012, with 144 ha lost.
Worst year: 2012, with 483 ha lost.
| Cayenne | Saint-Laurent-du-Maroni | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 1,870 ha (better) | 4,320 ha |
| Share of its forestOf what it had in 2000. | 19% | 17% (better) |
| Cleared for goodTurned into farms, mines or towns. | 1,730 ha (better) | 3,950 ha |
| Recent trend2021–2025 against the five years before. | Slowing down | Holding steady |
| Main known cause | Towns and roads (80%) | Farms, pasture and plantations (77%) |
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.
Cayenne
2017: satellite photo from July 2017 of a 5 × 5 km area about 7 km west of the city center.
Saint-Laurent-du-Maroni
2017: satellite photo from August 2017 of a 5 × 5 km area about 6 km west of the city center.
Trees
Which has more trees, Cayenne or Saint-Laurent-du-Maroni?
Cayenne has more tree cover: 48.5% of the land within 2 km of its center against 42.4% around Saint-Laurent-du-Maroni, or about 94,163 trees against 69,266.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Cayenne | Saint-Laurent-du-Maroni | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 94.2K (better) | 69.3K |
| Trees still neededTo reach the target. Fewer is better. | 0 | 0 |
| CO₂ absorbed each yearBy the trees already standing. | 2.1M kg (better) | 1.5M 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
Cayenne vs Saint-Laurent-du-Maroni: your questions answered
Is Cayenne cleaner than Saint-Laurent-du-Maroni?
On air quality, yes, right now: Cayenne reads AQI 48 against 55, 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 7 days, on modeled daily averages, Cayenne averaged AQI 22 against 37, and it was the cleaner of the two on 7 of those days.
Is it safe to exercise outdoors in Cayenne and Saint-Laurent-du-Maroni today?
In Cayenne, at AQI 48: Air quality is satisfactory for everyone. In Saint-Laurent-du-Maroni, at AQI 55: Unusually sensitive people should consider limiting long outdoor exertion.
Which has lost more forest, Cayenne or Saint-Laurent-du-Maroni?
Saint-Laurent-du-Maroni has lost more: about 4,320 ha of forest within 10 km of its center from 2001 to 2025, against 1,870 ha around Cayenne. 3,950 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Cayenne or Saint-Laurent-du-Maroni?
Cayenne has more tree cover: 48.5% of the land within 2 km of its center against 42.4% around Saint-Laurent-du-Maroni, or about 94,163 trees against 69,266. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Cayenne and Saint-Laurent-du-Maroni need?
Cayenne needs about 0 more to reach its canopy target of 30%, and Saint-Laurent-du-Maroni about 0 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Cayenne and Saint-Laurent-du-Maroni 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. Cayenne is read from a nearby ground station and Saint-Laurent-du-Maroni is a model estimate, so the two are not quite like for like. Nothing is adjusted for population, city limits or climate.
How often does the Cayenne vs Saint-Laurent-du-Maroni 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 19, 2026 and Sep 2, 2026), and the forest figures are published yearly.
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